We have a 12KW standby generator on our home. It runs on natural gas. 200 amp auto transfer switch. It will run our whole house. Water pump, furnace, AC and anything else we have except the electric oven. Does not cost much to run on NG.
You could use your RV generator, It will require some wiring to get power to the house. It will run your furnace in cold weather. I was able to use a 5000 watt generator to keep water pump, furnace, freezer and fridge, Plus TV and lights.
If you are going to be in SE MI. I got mine from and installed by
Marks Outdoor Equipment in Notrhville, MI.