I routed a furnace pipe down to the basement, so whenever I heat the RV, it provides heat to the water and dump area. I also have the little 12 volt heater in the pump area that goes on automaticly below 40 some degree.
To keep heat where you live or where you sleep, you can buy some magnet stuff at Home Depot that you cut to fit over the heat vent so you can block the heat and keep the living or sleeping area warn as you wish.
I also installed some extra foam insulation in the basement doors opening. I camped down to minus 15F so far for many days.