Jan-Feb-March in Mesa, AZ- few questions about heat sources

Mesa does not allow for refilling any propane tank in parks. You either have a replacement delivered and attached, or you go and get refills. In our case, that would mean unhooking motorhome, etc. So, we always tried to make sure we had a full propane tank when setting down and then used electric space heaters and very, very, very seldom did we ever run the furnace. It has been a few years since we hit the freezing point as a low around here.