Propane or genset for refrigerator when on the road

100 gallon is not correct but it really does not matter. A 100# tank will last "forever" if only used to keep the fridge running. If you only need to keep the fridge running the correct way to do this is by using your propane supply. If you need to run A/C while driving and you are forced to use the generator to allow for this option I would switch the fridge to A/C but even then, it really would not be necessary. The fridge on propane 24/7 (except while fueling) is still the most efficient use.