Erica, I live in Cowes, and know Thorness quite well, from days well before Park resorts took it over. It is mainly a static home park, and caters for those mainly. The touring park is at the top of the site, which is on quite a slope, and the roadways are not that good.Cowes as a town is something and nothing really, it only comes alive for a few weeks in the summer,end of July and first couple of weeks in August, and caters for the sailing fraternity.I would say that disabled access is somewhat dismal and there is not all that much to do in the town itself, unless you like shopping in sailing type shops.
Whilst most places on the Island are on, or have pretty steep hills in them, or around them, my personal opinion for a good place for disabled access has to be Ryde, secondly Sandown and thirdly Shanklin.
Ryde has the best in the way of places to eat, pubs, and leisure activities, a wonderful seafront and has tenpin bowling etc, which is not availabe anywhere else on the Island.
A good site, quiet but really nice, and has just had a new toilet block built, Beaper Farm at Ryde, and at a fraction of the cost of Thorness , (two people, electric hookup, van and awning.