I spent a winter in my Motorhome in KAnsas City back in 91 and I had an external propane tank, skirting around the outside, heated water hose and a 60watt bulb in the back of the refer compartment.
I could not imagine Fairbanks for the winter. The electric heater will not carry you thru the winter. Is there anyway to have a bigger propane tank delivered for the furnace? Please let us know how you make out as the temps fall.
Take care up there.
Tom and Gloria 2017 Newmar Ventana 4369, TOAD: 2015 GMC Canyon, Blue Ox Towbar, Baseplate and M&G Braking System