I've used a diesel parking heater for several years for inexpensive heat. I've got one similar to this: https://www.amazon.com/dp/B09SPBLGQD I found mine on ebay for about US$100.

You will also likely need a larger capacity gas meter. Get a plumber to spec out the size of the gas line to the generator.

Things to think about:

• Inverter generators generally use less fuel, especially if you aren't running at near full capacity.
• Many inverter generators can be paralleled together to double their capacity when needed.
• Get a 240V generator if you plan on connecting it to your house wiring.
• The least expensive safe and legal way to connect to house wiring is with a power inlet and an interlock on the main breaker box. Use 10ga wire for 30A, 8ga wire for 40A, and 6ga wire for 50A. An electrical permit is generally required.
• If you are going to be running it for an extended time, you don't want to be running it at full capacity. It will last longer running at 50% than at 90%.
• A MicroAir EasyStart on your AC will help with the startup surge. Very simple install, no electrical permit required. If your AC has a Locked Rotor Amperage of, for instance, 40A the EasyStart can bring it down at least 50%, allowing a 5000w (~20A) generator to run your AC.
• If you have Natural Gas available, it will be much less expensive than Gas, Diesel or Propane. NG will also be more available during the aftermath of a natural disaster. NG will give you about 65% of the power of gasoline, so a 30A generator will give you about 20A on NG.
• Many gasoline or dual fuel generators can be modified with a "snorkel" adapter for propane or NG use. There are kits for dual fuel or tri fuel. Replacement carburetors for dual fuel can often be found on ebay and amazon.
• Open frame generators are louder than closed frame, but are lighter and cheaper.
• Closed frame generators run hotter then open frame, but are much quieter.
• Portable generators generally don't have an oil filter. Get a magnetic dipstick and drain plug for those, especially if new. Metal shavings in brand new gensets is a killer.
• Generators damaging electronics is largely an exaggeration. The surge, spike, sag or other nastiness takes place when a standard generator shuts off. Turn off the generator breaker before starting or shutting down the engine. Throwing the generator breaker prevents that from getting to your electronics. It is a good idea, even with inverter generators.
• Don't use generators to run electric heat. A diesel parking heater or propane heater is much more efficient. Fuel heaters or even wood stoves are more efficient sources of heat than electric from a generator.
• Carbon Monoxide from generators kills about 70 people each year in the US. Don't operate a generator in the house, garage or any connected structure.

Things to think about:

• Inverter generators generally use less fuel, especially if you aren't running at near full capacity.
• Many inverter generators can be paralleled together to double their capacity when needed.
• Get a 240V generator if you plan on connecting it to your house wiring.
• If you are going to be running it for an extended time, you don't want to be running it at full capacity. It will last longer running at 50% than at 90%.
• Propane in a large tank will be less expensive than gasoline, but you only get about 80% of the power from your generator.
• Many gasoline or dual fuel generators can be modified with a "snorkel" adapter for propane or NG use. There are kits for dual fuel or tri fuel. Replacement carburetors for dual fuel can often be found on ebay and amazon.
• Open frame generators are louder than closed frame, but are lighter and cheaper.
• Closed frame generators run hotter then open frame, but are much quieter.
• Portable generators generally don't have an oil filter. Get a magnetic dipstick and drain plug for those, especially if new. Metal shavings in brand new gensets is a killer.
• Generators damaging electronics is largely an exaggeration. The surge, spike, sag or other nastiness takes place when a standard generator shuts off. Turn off the generator breaker before starting or shutting down the engine. Throwing the generator breaker prevents that from getting to your electronics. It is a good idea, even with inverter generators.
• Don't use generators to run electric heat. A diesel parking heater is much more efficient. Propane or kerosene heaters or even wood stoves are better sources of heat.
• Carbon Monoxide from generators kills about 70 people each year in the US. Don't operate a generator in the house, garage or any connected structure.

Things to think about:

• Inverter generators generally use less fuel, especially if you aren't running at near full capacity.
• Many inverter generators can be paralleled together to double their capacity when needed.
• Get a 240V generator if you plan on connecting it to your house wiring.
• If you must use a 120V generator, you can bridge the two "hot" lines. This can be done inside the extension cord running from the generator, or with a plug that goes in one of your 240V appliance (Dryer, etc.) sockets. This MUST be disconnected before going back on mains power, and isn't recommended for a long term solution.
• If you are going to be running it for an extended time, you don't want to be running it at full capacity. It will last longer running at 50% than at 90%.
• A MicroAir EasyStart on your AC will help with the startup surge. Very simple install, no electrical permit required. If your AC has a Locked Rotor Amperage of, for instance, 40A the EasyStart can bring it down at least 50%, allowing a 5000w (~20A) generator to run your AC.
• Propane in a large tank will be less expensive than gasoline, but you only get about 80% of the power from your generator. Common sizes of home propane tanks are 120, 250, 500 and 1000 gallon. They can be installed above or below ground. Small "BBQ Grill" 20 pound tanks, which typically hold 4 to 4.5 gallons, will often be more expensive than gasoline.
• If you have Natural Gas available, it will be much less expensive than Gas, Diesel or Propane. NG will also be more available during the aftermath of a natural disaster. NG will give you about 65% of the power of gasoline, so a 30A generator will give you about 20A on NG.
• Many gasoline or dual fuel generators can be modified with a "snorkel" adapter for propane or NG use. There are kits for dual fuel or tri fuel. Replacement carburetors for dual fuel can often be found on ebay and amazon.
• If NG isn't an option, consider using propane, or getting an Off Road, or Farm Use permit for your gas or diesel. It will let you purchase fuel without paying road taxes. In TX you can also just save your receipts and get a refund for road taxes. Your state will likely be different.
• Open frame generators are louder than closed frame, but are lighter and cheaper.
• Closed frame generators run hotter then open frame, but are much quieter.
• Portable generators generally don't have an oil filter. Get a magnetic dipstick and drain plug for those, especially if new. Metal shavings in brand new gensets is a killer.
• Generators damaging electronics is largely an exaggeration. The surge, spike, sag or other nastiness takes place when a standard generator shuts off. Turn off the generator breaker before starting or shutting down the engine. Throwing the generator breaker prevents that from getting to your electronics. It is a good idea, even with inverter generators.
• Don't use generators to run electric heat. A diesel parking heater or propane heater is much more efficient. Fuel heaters or even wood stoves are more efficient sources of heat than electric from a generator.
• Carbon Monoxide from generators kills about 70 people each year in the US. Don't operate a generator in the house, garage or any connected structure.