The Class A we just sold the previous owner plumbed a quick disconnect from the propane to the interior of the Motorhome and then He used the Big Buddy at night in the bedroom or living room only then in the morning would run the RV gas heat to bring the entire coach up to temp. It saved him a lot of Propane not heating the entire RV at night heating only the rooms he was in.
You could also install a diesel heater (like used on Boats) you would need a small diesel tank however you can also install a 50 gallon aux tank in your Diesel truck to use to refuel the small RV tank that would feed the diesel heater. those heaters are very efficient, we have a Espar Diesel heater on our 48' boat although we have 600 gallons of Diesel fuel tanks on board.
Here is a Diesel Heater made just for RV's
https://www.amazon.com/Eberspacher-A...28918423&psc=1
