Yep, we have a 50 amp rig with residential fridge that's powered off the batteries and tow vehicle alternator via an inverter and transfer switch when on the road. The way our CheapHeat system was installed, the strip heat is using 240VAC across L1 and L2, so it doesn't work if only 30 amp service (or miswired 50 amp service) is available - which is basically never for us in the RV parks we frequent. So, it does have its limitations, but since it came on the rig, I figured if I have it why not use it?
Another advantage is that, unlike the ceramic space heaters we used to use, the CheapHeat system keeps the basement warm just like the propane furnace since it uses the same ductwork.
Rusty