You have to use a battery powered thermostat. RVs use 12 VDC for the control power and all house thermostats use 24 volt.
There are a few thermostats on the market that can be used on an RV. Be sure and keep a set of batteries for the thermostat. Also, the connection is not a wire for wire change. House thermostats do not have a hi-lo fan switch as well, but a switch can be added.
Here is a link to use a Honeywell replacement. I would not use a programmable on in an RV.
https://www.youtube.com/watch?v=6CPtV_iX9GQ
Ken