To answer the questions on are available power. We are parked next to an out building that is on a sub panel from the main service in the house. I looked at the size of the wiring coming out here and it was big enough to support a 30 amp breaker but nothing bigger. I installed your typical 30 amp rv box from Lowes. Inside the sub panel the lights for the building is on a 15 amp breaker and the outlets for the building are on a 20 amp breaker. The heat tape and most recently the bedroom heater is also plugged in to an outlet. Believe me I would love to install a 50 amp service but I don't think the wiring from the house would handle it. I welcome ideas if you think it can be done safely.