Dry Camping - Heat with Propane, or electrically w/Inverter?

We do mostly dry camping. A Buddy Heater is a great way to offset the use of the 12v/propane furnace. We use the Buddy at night before turning in, then set the 12v/propane furnace to 55-60 degrees to keep the belly and pipes from freezing. In the morning we turn on the stove to make coffee and fire up the Buddy again. With my 450w of solar and four 6v golf cart batteries we can do this routine in temps as low as 07 degrees and manage well. I normally have 85% battery left in the morning.