I have a new device driver called 'Remote Thermostat' that I think accomplishes this. It has no 'smarts' so is purely a virtual device for a remote MQTT thermostat managed by some other controller/device. That's available now should you want ?
There maybe other such remote devices needed where the virtual driver within HE has some smarts and therefore is in conflict with a remote device. Perhaps window shade is the simplest of such an example with it's timed behaviour.
