2-way fridge question

We never run our frig when traveling and once everything is frozen and cold, it stays cold for 6-8 hrs as long as the doors are not opened much. When we stop for lunch like in a rest area, we will run the frig on propane for the half hour or so that we are there. We have never seen the temp in the frig go above 36-38 degrees even after a few hours. I would turn the frig on 48 hr before leaving - after 24 I'd load already frozen into the freezer and already cold into the frig. Everything should then be set for travel the next day. I wouldn't go more that 6 hrs without running the frig in some manner for awhile though. Not sure how much longer it will go before warming too much. Do not try to store ice cream when traveling. We are full-time, so the only time the frig is off is when traveling, or defrosting it.