With 2 12v batteries, I'm lucky to make it thru the night when I boondock. That darn heat runs almost constantly thru the night because it gets down into the 30's even in the middle of summer when you are 'docking at 10,000+ feet asl.
I'm looking at four 6v batteries and if I can fit it 400 watts of solar power for my camper. I can pull that off financially, I may never need to run the generator.
I did pick up a small catalytic heater but refilling those 1lb propane bottles that are lucky to last 4 hours on high are a PITA.
I'm thinking of getting a vented catalytic heater that is run on 12v power for the venting. It'll be mounted recessed in a panel that is not used. I think it'll save a lot on batteries and propane instead of running the heater all night.
Already replaced all of the incandescent with LED lights. Water pump should always be off unless you are using it. Had a water compression fitting fail on me 2 campers ago and it made for a big mess.