It's been a few weeks since our furnace, for as yet undiagnosed reasons, ceased to function. While it's been unusually cold here (the Snowbirds are getting pissed off - lol), I've been pleasantly surprised how cozy using just our electric oil radiators keeps the house. Our front rooms are open floor plan, so it can still be a bit chilly, but the bedrooms that we can close off are quite toasty in the night.