First of all IMHO this isn't necessarily and only a disability issue. 'Many' of us use scooters who do sport venue RV'ing to get to one end of the venue and back to the RV quickly.
You could get a lot of good advice right here in the general rving forum. :W
Just an observation.
We had a disabled vet Rv'er where I was staying and the mobility scooters are very heavy. That poor guy got stuck 20 times a day every day, where fellow campers had to constantly push him out.
They are good on concrete but when it comes to a CG I don't think that would be your best bet.
We dog show and some of my fellow friends with knee problems bought the three wheel or two wheel rechargeable battery scooters. They worked 'great' on all types of terrains which get tricky at show venues. So do the 2 wheel ones!
The three wheel battery scooters are light weight to pick up and put in RV and no balancing needed when riding on one! :C