The size of your tanks makes a big difference in how long they last. We can get a week of showers, bathroom, cooking for DW & myself when there are no water or sewer hookups. We filled our propane tank last year. All of our tanks are fairly large. We have a small electric heater that keeps the bedroom very warm. Southern IL. would be a lot easier to keep warm in winter than North. Not all RVs are created equal. Some have great insulation and some have none. That is the reason your questions can't be answered accurately