If you are not using the RV
1. If no water in a tank don't run the tank heaters. They require some water to absorb and distribute the heat.
2. Drain the hot water tank. Remove the anode.
3. Drain all water lines.
If you are not using it, I would winterize.
If using it, put some water in each tank (5gal). Run the tank heaters. Set furnace thermostat to 50deg.
Also use your fireplace on low to augment the furnace. If you have electricity and water in the water heater, turn on the electric heater. Verify water in the tank first before turning on water heater.
Get a remote thermometer to monitor your outside, basement and inside temp.
https://www.amazon.com/AMIR-Thermome...mometer&sr=8-6