I'm looking to replace a "dumb" thermostat in my house.
My biggest problem is, the Family (well MIL) will be the primary user of said thermostat. Were it up to me, i'd just duplicate the setup I have in my detached garage (ESP32 and 4channel relay board, with remote temp sensors).
My second biggest problem is many of the smart thermostats requiring internet access and control only being available through their External API. Ideally I'd like something that is 100% local control, with opt in for any remote data.
What setups do you have? do you like it? is it "normal" person friendly?
+1 for the T6, I have one that was a perfect drop-in replacement for my previous Honeywell thermostat. The only bit of fiddling I had to do was enabling Auto Heat/Cool mode in the ZwaveJS2MQTT dashboard.
I'd also recommend the SimpleThermostat Lovelace card, it's much more customizable than the default card.
This is what i went with. I haven't setup Home Assistant yet but i like the thermostat so far. I dont believe mine comes with schedules but there are different models.
I've had an ecobee for five years and it's been great... EXCEPT for that when they were doing a server migration or something a few years back. I swear for several months it was completely unreliable with Google Assistant and the Android App not being able to reach it half the time.
Like the OP said, it uses an external call to cloud servers and you have to trust that those servers will stay online and be reliable. It's been rock solid for the last few years so I think I was just part of some growing pains, but my god I was pissed during that time and about to buy a Z-wave thermostat.
An ecobee should work as long as you have a C wire. I haven't tried the ecobee integration, but instead I use it with the built in Homekit integration. The only downside to HomeKit is I can't put the thermostat on a separate VLAN from Home Assistant.
This is my solve for this stuff too. I do all of my automation through HomeKit because it will work on a local wireless without an internet connection.
Biggest problem with staying in the HomeKit ecosystem is that Android phones are kind of fucked if you lock things down to pure HomeKit.
Ecobee hits all the wickets you're looking for. Local control through homekit, cloud based as well, and simple enough for my wife (the non-techy) to figure out.
I have been very happy with my venstar colortouch. It has a well documented local API, with a cloud option and mobile app if you're comfortable with that. The HA integration is great as well.