In winter for the main thermostat, 68 days, 65 nights; and 60 for the separate den temp control. We also use the fireplace a lot, especially on weekends. Our house is drafty due to all the windows (over 40!). During the transition season of autumn, we only turn it down to 67 nights until our bodies, and our cats, have had a chance to acclimate a little to the new lower temps. The dog loves cold and snow.
2001 Trek 7500 FX, converted to a hauler - Serfas
200? Marin hybrid - Selle San Marco
2004 Trek 5200 - Avatar
2011 Trek 6.2 Madone - Ruby