wow- I feel like a major winter wimp here. Our house is very old and very under-insulated (we're working on that one exterior wall at a time). We have it set at 68 in the evening and 73 when we're home.
One winter we lost power for a week during an ice storm. Our house got down down 61 and I swear I almost froze to death. I don't know how you people do it below 61.