I’ve traveled from Texas to California with kegs and set them up successfully and everyone has enjoyed the brew. I have traveled from my house in Fort Worth to the Cowboys stadium to tailgate and we’ve successfully enjoyed the brew. The secret is keeping it as cold as possible. I stored the kegs in what would typically be a kitchen trash can and put lots of salt with the ice(and small amount of water) to make sure the temperature is as low as possible. The lower the temperature the better the co2 stays in your beer. I have a portable co2 gauge and use cartridges which I’ll post in an edit since I’m on mobile right now but if I’m staying local enough I just travel with my 5# tank and gauges.

Edit: This is the gauge I have

This is the tap that you'd want to use

These are the tanks that you'd use

Sure it's a bit pricey, but, it's portable and that's the point.

Mine were always done with 5 gallon kegs too. I do have a 1.5 gallon keg and this is it if you're interested but again, I've only done what you're talking about with 5 gallon kegs, but, that doesn't really change anything.