To be fair, at $0.04/kWh, even at very low outdoor temperature, a heat pump at COP only a little bit above 1 or even an electric resistance heater is not very expensive to operate. If you have anything resembling decent insulation and you heat only a small space, heat can be very inexpensive. Even in an old, uninsulated, drafty house, you can fudge it cheaply with window insulating film and by hanging fabric on the walls. (Those cheap cut-to-size cellular window shades sold at many home improvement stores also have excellent thermal performance.)
It gets tricky if you want a civilized humidity level, though. You need to control leakage to achieve decent humidity and you need to control condensation to avoid damaging the window trim or other parts of the structure and to avoid growing mold.
It gets tricky if you want a civilized humidity level, though. You need to control leakage to achieve decent humidity and you need to control condensation to avoid damaging the window trim or other parts of the structure and to avoid growing mold.