Sounds good enough.  Empty room equals no need for AC or heat, which is true, but when you rely on motion sensors to achieve this it has one huge potential problem.  Guests don’t move much while they are sleeping.  This leads me to today’s idea.  A simple clip or stick on device that moves a small metal element side to side at programmable intervals. Place the device directly over the movement sensor and it would fool the sensor into thinking someone was moving around in the room. It would be silent, convenient, and easily could be added to any traveler’s bag.  A small battery would be all that was needed, and would last for many nights of consistent use, and keep the travelers room at the desired comfortable temperature.  It certainly would be worth it, if it keeps you from waking up in a nice warm sweat.  Ugh!

(Yes, there are other uses for such a device)