How much electiticy costs to run small RV heaters?

My neighbor had a similar problem. He let a friend set up his 26ft camper on his property for 3 months while he worked in the area. My neighbor saw a significant spike in his electricity bill during the 3 months.

So, yes, it is possible.

If I were you, I'd throw in a few bucks each month and share the costs.

Gerry