OK, I'll be the first to start the debate!
First, what kind of refrigerator do you have? Is it a residential or an RV style.
If residential, why can't you run it on an inverter powered through your camper battery?
If an standard RV type, why don't you run it on gas?
So here now starts the great "to run or not to run your RV refer when on the road debate!"
We have an RV refer and never shut it off. It runs on gas when traveling. We have no problems. Ice Cream stays frozen that way!
But, to answer your question a little closer, assuming you have an RV refrigerator and you choose to not run it when in transport, how long will food stay safe?
Bottom line, that depends upon the outside temperature.
More than likely, things in the refer will be OK after 6 hours. Even without refrigeration, meats can usually sit unrefrigerated over night, sometimes 10-12 hours. Eggs can go for days without refrigeration. Milk will go get warm, and spoil within a couple hours. Ice Cream will melt immediately. Frozen foods will be pretty much thawed out in 6 hours, even a 20 pound frozen turkey will be almost thawed in 6 hours.
So really, if you have no power to your refrigerator at all, it really depends upon the outside temperature and how much cold-loss the refrigerator suffers before the inside gets above a safe level, and then it will take a few hours before things begin to spoil.
No one can really say. You can test the refrigerator with a sacrificial cup of milk inside a cold refrigerator, then kill the power. See how long it takes to spoil.
