Nest temp sensor

Nest is starting to ship their temp sensors. As per their own documentation, the sensor is not very smart so no motion detection or any other sensors.
Can we find a way to tell nest to start/stop using the sensor? That way we can automate using other components (like motion sensors). And depending on how the API works, maybe we can use other temp sensors (not from nest) and have home assistant control the thermostat based on those.