What I also realized you could do to extend this mod is the following (assuming large load rated cables like those used in wiring a house):
- Add a permanent mount trickle charger like those waterproof ones seen on boats. 
 - Add an extension plug designed to turn on the block heater and a battery warmer when the temperature is below a set amount. 
 - Route a plug into the cabin so you can run electronics while plugged in camping. 



