Like I said too, no dumb questions here. Maybe a dumb answer
I'd don't drive with propane on either. I've been on the road for 6-8 hours and my fridge has been fine. Like Beth said, plug in and cool down the day before you leave and put cold stuff in. I do that and transfer food from home fridge to trailer in the a.m. Before I leave. Now, on this upcoming trip, if my trailer is going to be parked for awhile, say out enjoying the sights, I wil turn on gas and turn on fridge till I'm ready to leave. It is illegal to gas your vehicle at a gas station with propane turned on, so be sure to turn it off.
At campsite, I back in or pull through,make sure I'm level, unhitching uf not just overnighting, then plug in to electric so fridge can run while I put down stabilizers, set up camp etc.I don't use my stove either, or haven't yet, so don't turn on propane till I need to use HW tank and when done, turn HW back off. Pump I sometimes leave on, sometimes not. I definitely turn it off when I leave the trailer, just in case something springs a leak or something. I carry about three empty gallon milk jugs and sometimes if I'm close to bath house, will go over and get hot water from there to do dishes, wash up, wash hair or whatever, rather than use my water and propane. I think it's because our state parks don't have full hookups, saves my on board water when I am in one spot for a few days.
When leaving, electric is last thing I unplug so keeps fridge cold while breaking camp.