As nosticks said - the only heat source for the furnace is propane.
On the 2014 Hurricane (at least my 32A) - there is no fresh water tank/pump/valves in the basement - it is all in the RV... so running space heaters is an option. (Unlike the Challenger which relies on the furnace heating the wet bay in basement to prevent freezing.)
If you will be below freezing - be aware of the tank drain pipes... Nothing heats that area... Cracking a black water drain pipe wouldn't be any fun. (Would really have to be below 32 for a bit... Not sure you are getting that cold in SC...)
These rigs are not insulated like your home... and as the temperature outside drops, the propane usage goes up significantly. I remember an unexpected snowy Christmas in Arkansas a few years ago - could almost watch the propane gauge go down until I added a space heater.
Not yet retired...
Florida (Michigan transplant)
2014 Hurricane 32A
2000 Infinity (previous)