Also, be very careful about temperature. I have RR (relapsing-remitting) MS, and while I haven't yet had mobility issues to the point of needing a wheel-chair, even when I'm not having an "episode", I have problems regulating my body temperature (namely, I get overheated very, very easily.) I imagine on top of the boys' GACs (for AS), I'll probably have to get one myself, for the "wait in shaded/cool" area (sigh.)
Many people with MS (myself included) experience extreme fatigue in the mid-afternoon when they have flare-ups (often brought on by stress, illness or overexertion.) One minute, you feel fine, the next, like every single muscle in your body is going to collapse if you don't lie down immediately (and sitting just won't do.) So I highly recommend planning resort rest periods during that time.
Good luck and have a wonderful trip.