Could be done. Biggest tasks plumbing into the coolant system and fitting a stand pipe in the fuel tank.
Electrically it's largely independent of the car, but the factory fitted ones have a feed from one of the control units that is live (12v) when the engine is running. This passes through the temperature switch mounted on the front bumper iron. When it's cold enough to close the switch the 12v is sent to the start terminal. Either wire it this way or just have a switch / remote relay to manual,y start it whenever.