I'm running a 160 degree thermostat in the engine but during these colder outside temps, engine temps hover between 150-160, and because of that the car's inside cabin heat is lacking, so I would like to be able to simply turn up the engine temp to 180 during these times.
The engine runs on propane which likes the lower 160 operating temperature.

An electrical fan might do the trick, although the stock (wornout/free wheeling) thermo-clutch fan and fanshroud have no problems keeping the engine cool, so installing more electrical stuff in the car for this seems a bit overkill.