Thermostat wiring delema

I have a 2012 Komfort 5th wheel with a single zone Dometic heat/cool thermostat. My complaint is that the lowest heat setting is 60 degrees. That's just too warm for overnight or short-term maintenance heating. I have found another Dometic single zone (min 40 degrees) that would appear to be a good replacement, but it comes with a plug-in connector and mine is hard wired; 8 wires soldered right into the circuit board.
Has anybody else encountered this problem? Do I need to take it to a service center?