Generic thermostat with front end selectable entity

Problem: I have multiple DHT sensors around my house but only one central heating setting e.g no radiator control or zoned heating. I want the ability to reference the heating against any given DHT sensor rather than a fixed location.

Idea: a generic thermostat where you can pick the heat entity from a dropdown. That way I can (on a case by case basis) heat until a specific room reaches the temp I want.

Does anybody have any ideas or code on how to do this?

I know this can be achieved by rad controls but looking for a software fix not a hardware fix.

I think a triggered sensor could work.
The trigger would be a dropdown.
The sensor part is a template to get the temperature from the dropdown value.

Then you add this sensor to the generic thermostat

You can probably add some that would be the average of a few sensors or of them all.