Heater Specs on 2019 Palomino Puma XLE Lite 27RBQC

I would call the dealer and have him go look at the unit to find out the heater size. I'm sure it is going to have a propane furnace sized appropriately by the manufacturer for that unit.

Keep in mind that almost no RV's are suitable for extended winter use. Spring and Fall are ok but the insulation in most RV's is very thin and most will not be comfortable in extended cold weather without modification.
Barney