Okay - you have a car, a hybrid. Fine.

Most people are not particularly productive in coffee shops. They may be fun and social but not productive. Some stores get cranky about you holding down a table for long periods.

Either a separate hotspot (I use a Netgear Nighthawk 5G) or phone-as-hotspot (I use an iPhone 12 mini) work fine in most places. You'll do best with carrier diversity (say AT&T on one device and Verizon on the other).

There is no reason you can't charge off a hybrid. Some but not all cars both ICE, Hybrid, and EV turn off the power points when the car is off but that doesn't have anything to do with propulsion. I charge stuff off my Accord Hybrid all the time. Your best bet (<- opinion) is a 12V start battery just like the one in your car in parallel with the standard battery and a relay that charges that battery when the car is on and isolates it when the car is off. Any RV, marine, or snow plow dealer can help you. If you're near Annapolis MD I can help you.

You need more water. You should have at least one gallon per person per day. I like the Sceptre 5 gal "Jerry" jugs you can get at sporting goods stores, RV outlets, and marine stores. Get a jiggler like https://www.amazon.com/Siphon-Original-Safety-Grade-Valve/dp/B01N5MTGQS/ so you don't have to to pour water into a cup. You can buy water in 1, 2, and 5 gallon containers, but refilling your own is easier and more efficient.

Get the auto/air adapter for your laptop so you can charge off 12VDC.

Get a small inverter like this https://www.amazon.com/BESTEK-300W-Power-Inverter-Adapter/dp/B004MDXS0U/ (I have two of these for various applications). Note that you can only draw 6A from a cigarette lighter plug continuously, so 72W. You want a slightly bigger inverter for surges and to keep it from overheating.

Pen sized LED flashlight. Blue tape. Small tools. Small USB powered fan. Powered USB hub (get one that is 12VDC on the hub side of the wall wart).