Hey TX,
I rode in the local MS150 about five or six years ago, for the first 35 mile stretch (and that
was a stretch, lol).
We consumed
lots of calories and water during the ride. They fed us well along the way. I still have my T shirt from that day. It was about 95 degrees with full sun and high humidity. I will never,
ever try that again!
Also, I was taking Copaxone then, and when I did my morning shot in my thigh, I hit the muscle and it felt like I'd been shot in the leg with a gun.

Ouch!!!
There was a 75 year old lady riding too, and she was a bike marathon regular. She had been on a 100 or 200 mile ride in Alaska and part of it was riding through snow accumulation!
She and I were at about the same pace and we both stopped at 35 miles. It was great, but I was
completely worn out for about a month.
So, needless to say, I'm in awe of you or anybody with MS who completes the 150 miles!