My only experience with RV charging was while tent camping in extremely rural Nebraska during the 2017 solar eclipse. There were RV slips nearby and I thought "well, why not?" With my PHEV, I didn't necessarily need to charge it up much, or at all. There was no ranger around so I pulled up to one, opened the RV service cover and there were 2 120v and 2 14-50 240v outlets. Yup, it was on. Apparently, they all were. This was a spot where no RV was parked for at least the 2 days I was there, so none of the other eclipsers (word?) was going to get nicked for my crime.
I might have just got lucky that time, but I learned a trick for future BEV emergencies, if ever the occasion applies to me. Though the intention wasn't as much to poach, but to learn something about RV utility hook-ups. I guess that I owe Hemingford, NE about 4 kW worth of juice. I took a picture of my crime to incriminate myself.