Our son uses our fiver whenever he and his girlfriend come home for holidays. They prefer the privacy, as do we. We also have two young daughters and our three bedrooms are all being used.
They use a small ceramic heater in the winter, but use our bathroom facilities in the house. During warmer weather, the bathroom facilities within are used.
NOW, if my dad was coming to visit, he would stay in the house. (He only lives about a mile away). He is 80 years old and has bad knees and getting in and out of the RV is a chore for him.
I guess you have should just ASK HIM!! See what HE thinks about the idea since it doesn't matter one little bit what we think.