We have a two story house approx 3,200 Sqft, dual zone heat/AC and programmable thermostats. Our bedroom is on the first floor, and we have a large great room with a 2 story ceiling. With the kids having moved out, we don't want to spend more for heating the house than necessary. We don't need to keep the 2nd floor warm, and can close all the doors to the 3 bedrooms upstairs, exposing the loft, hallway and second floor of the great room to the ambient temperature downstairs. The downstairs thermostat is in the hall near the great room and outside the master bedroom. The upstairs thermostat is at the top of the stairs in the hallway outside the bedrooms. Both thermostats are programmed to drop to 60F after 10PM, and come back on around 5:30 AM, and then about 68F the rest of the day. Should we cut back the thermostat in the upstairs during the winter months, or even off? If yes (to temperature), how much? Should we close the doors to the upstairs bedrooms? I should also mention we have dual fuel (electric/propane). Knowledgeable responses are welcome:) Thank you.

If you are not using the rooms turn off the heat BUT if there is a bathroom or any areas that have water pipes located upstairs you will have to temper the turn it all off situation because the pipes can freeze especially if the pipes are on a outside wall.

There will always be residual heat going up stairs because heat rises.

Also I would check those upstairs areas from time to time just to be sure no condensation forms on the outside walls and windows from lack of circulation.

You know your home much better than we do here so keep an eye out for and problems.