Ours is set to 55F. That temp keeps the pipes from freezing in the outer walls if the temp happens to drop to below freezing outside (which doesn't happen all that much). The furnace does kick on for half an hour at 6 am to take the house up to 65, but then shuts off again for the rest of the day.

My H works from home, but he sits in a tiny room surrounded by computers, so it's quite warm in there.

We also have a wood stove (a new one that is the right size for our house, finally!) and we use that to keep it comfortable when we are home like in the evening or on the weekends.