Proper placement of thermostat
The thermostat is what senses the temperature so you want it where you want the most accurate temperature which would be in the bedroom however all other rooms will be a little off. The hallway may provide a good mix of temperatures or all the rooms may be hotter or colder than the hall. I have been using the Honeywell 8000 series thermostat with remote sensors and getting good results. You can add up to 6 sensors and they will all average. Put the thermostat in the hall for easy access and install wireless sensors in the bedrooms. There are of course other brands with remote sensors, I am just not to familiar with them.