Definitely post back here on results if you can, curious how this turns out for you. Also curious what smart thermostat you favor.
I'm still renting so I've not really bothered with any thermostat yet. I used to have a Nest Learning thermostat when I was living in a place where they allowed me to install it, but I gave that away when I moved.
Haven't bothered with thermostats since, and likely won't until I've moved into my own place, but I'm hoping to find a thermostat that can run without cloud or at least, with an OSS cloud replacement.