I'm in the same boat... Spent a couple years looking for a wifi thermostat that didn't require a cloud service. Actually I purchased a couple and hacked on them

I'm in the same boat... Spent a couple years looking for a wifi thermostat that didn't require a cloud service. Actually I purchased a couple and hacked on them, but never hooked any of them up to my AC unit. Granted I had some pretty specific requirements (long list having to do with multiple zones/etc). Not to long ago I settled for a couple of the venstar T7900's. They aren't perfect by any means, but they are light years ahead of anything else I could find. In fact they have a whole bunch of options that harken back to some of the early programmable thermostats. For example, out of the box you can control the max cycles/hour, or the number of degrees of variance from the setpoints. Buried in the menus are a wealth of options, including a few for limiting features available to "unprivileged" users. Funny enough, they can be subscribed to the power companies remote kill features, but the user is still in control and can disable the feature, which is probably why they are excluded from my power companies list of "smart" thermostats that qualify for rebates. So, the cloud service can do a lot of things that aren't available from the published API, but running a local deamon and polling runtimes, setpoints, etc is all very straightforward, as is forcing a thermostat on/off from a server on the local network. Anyway, that is my .02 for a thermostat that isn't owned by $megacorp/etc and can be disabled at the wim of a company that decides paying for a bunch of cloud servers is no longer in their interest.