Hi rvingman,
When I rv I travel lots. About 1600 kilometers per month on average. When I am rolling I run the fridge and water heater on 120 volt, just as if I were on shore power.
When I stop, I run the RV very much as if it were an electric based coach. That includes all cooking. I can do one night at -6 C (20 F) comfortably without burning propane. In fact the last time I purchased propane was Feb 2012.
If I'm in one spot for a while then I do have to moderate my electrical use, or find some shore power. If I'm in boondocking mode, I run out of fresh water eventually although the original owner had added a 2nd fresh water tank.