Join multiple independent electrical heaters under one thermostat or one control hub
Since you have an Aube TH108, you will need a line voltage thermostat. They do make smart thermostats and wifi connected thermostats capable of switching line voltage.

If you want something like a Nest or EcoBee, you'll also need something like an Aube RC840T-240 to provide the 24 volts they expect and act on the low voltage signals they provide.