Add a "Master Room" of sorts
Sometimes I just want to heat the whole house to, for example, 22°C for a short time to create some heat. The region were I live experiences major temperature drops and the thermostats sometimes just don't pick it up that quicly OR our sensation is that it's much colder than it actually is.
Having a "Master Room" where I could set ALL of my connected thermostats to a certain temperature for a certain amount of time would be great. After the set time has passed, each should go back to their regular schedule.