And you CAN IGNORE the below about the generator auto-start. I see Phoenix now offers the EC-30 generator that has that feature.
II am unaware of any auto start facility or settings for the generator. In fact, that could be dangerous in case you had a window open or roof vent drawing in outside air.
I am wondering, do you mean auto start air conditioner? Where you set the thermostat to a temperature for cooling (or heating) and it cycles on/off as needed Iike your home thermostat?
Just about any thermometer that you can connect to a home WiFi system should work. You, of course, need a WiFi internet connection where you are parked.
I did a search on Amazon for "internet connected thermometer" and they listed quite a few. No idea how any of them work as I don't have one for the RV.