I've got a 1100 sq-ft rancher with a propane furnace. I worked the numbers and it's cheaper for me to heat with a couple electric space heaters, and use the furnace as back-up. My daily average over the winter is 50 kWh, and I only use one 420lb tank of propane each winter.
A few weeks back I had free access to over a dozen half-full 20lb BBQ tanks. I disconnected the 420lb tank behind my house and used a 4-foot POL extension hose to connect to the 20lb tanks lined in a row. Each half-full tank lasts about 24 hours. With my space heaters off my daily average dropped to 20 kWh, meaning I saved about $3 per day. Two weeks of savings made it worth my while. I'm back on electric heat, and the 20% left in my 420lb tank should see me through the end of April.
For the record I've also got a 40gal electric water heater set to 120?, one 46" LCD TV, one 110" projector TV, and 6 STBs. My computer runs 24x7 but my twin 24" monitors shut off after 20 minutes.