RE: Leaving tomorrow 13 degrees.
My Winnebago has a road heater on the lower dash. The engine coolant circulates all the way to my water heater and is fan blown.
RE: 2013 Itasca V-10
My opinion would be that it has not been used too much unless it has been lived in. Not enough use is hard on generators and engines and other mechanicals.
I am going a little above just the v-10. The V-10 has been spectacular since the early models.