Heaters
I'm in a climate where heat pumps work quite well, so I'm using that now (my office is in the garage), but before that I had some pretty good luck with a couple of electric heaters that look like old steam radiators on wheels. Filled with sealed oil, they get warm and toast up a room with more even heat than an air-blown electric heater. Much safer, too. Tip one over, no problem.
Of course, the price of electricity is based normally on natural gas prices. Sure wish we had a few more nuclear reactors going now.
A lot depends on how your heating system actually works. Oil? Gas? Do you get gas piped in or is there a tank in the back? Additional tankage, even filled while prices are low, would end up costing more than the gas would.