I live in the southeast US in a two story, 1970's home. The lower level is temperature maintained with a heat pump controlled by a lower level thermostat. The upper level is temperature maintained with a central AC unit controlled by a thermostat on a landing at the top of the stairs. There are three bedrooms at the top of the stairs, each with a vent from the AC but with no return air vents. There is one return air vent at the landing at the top of the stairs.
Here is my problem:
If I open the bedroom doors for circulation, the thermostat will read the temperature, but the cool air will travel downstairs and be wasted.
If I leave the doors closed to keep the cold air in the rooms, the thermostat temperature always reads and keeps running pumping more AC into the rooms.

Question: should I move the thermostat into one of the bedrooms?

Question: should I move the thermostat into one of the bedrooms?

I would say yes, especially since there is no outlet vent in the upstairs hall. I've always had our upstairs thermostat in the master BR - which allows you (not the kids) to control the setting and ensures a comfortable temp in the BR. You may have to adjust the outlet vents in all three BRs to ensure consistent heating and cooling in each room.