I don't know if this works with your specific unit, but Mitsubishi makes a thermostat adapter where you can use a conventional thermostat. You could then use any Ecobee, Honeywell, or similar off the shelf thermostat.
The adapter is a bit costly and you may lose some specific functions. It is limited to the way a normal thermostat would work. But it could be in theory completely local, and you get a real thermostat you put on a wall with no batteries or remotes to lose.
I don't know anything about this company below, other than it came up in a Google search. This is simply an example of the adapter.
