My Mom and Dad take turns using a little, 3-wheel, folding, battery powered scooter. Sometimes, my Dad uses it to pull the blue honey wagon to the dump station, like a trailer. The scooter is very portable and not too difficult to lift, especially if you take the battery pack out, first. It saves some wear and tear on them, and they can get around more/farther. They full-time and could carry two of the scooters, but I think my Dad still considers the one scooter my Mother's, so he doesn't take any claim to it (he still rides his motorcycle, occasionally). I know where he's coming from.
I still use a bicycle, often our trips center around mountain biking, but most of my exposure to a campground comes from taking a walk after dinner.