I haven't camped since the early 90's but we stayed at Arrow Head State Park. The facilities were good but the heat was not so good. We started out in a tent and ended up sleeping on the picnic tables. I liked the showers.
I'm sure you can still get a room if you're willing to drive a few miles. I've stayed at the Budget Inn in Nacona numerous times. It's about 50 miles east of Wichita Falls. Not fancy, but much better than trying to sleep outside in the heat. You need to be as rested as possible, especially if you're doing the full century.
If you anticipate camping you could check the forecast before the event, sometimes it isn't "hotter than hell" on that weekend. I've seen lots of tents set up around the MPEC, I was just glad I didn't have to be one of them.
I seem to remember that in years past there have been alternatives on the HHH website for places to stay. Maybe not the best accommodations but better than 100F outside.
LOL!! Last 3 years I talked him into driving to the start line! Only problem is that he is sooooooo slow I have to wait on him to get to go get a Scotty Burger.
I've changed my routine in recent years. For several years there was a great smoothie stand near the entrance of the MPEC so I would go by there, buy a big smoothie, then head to my car and leave. My father was always waiting for us at home with lunch ready so I couldn't hang around. One year maybe about 5 years ago I couldn't find the smoothie stand but I did find a tent selling beer so I bought a beer instead. Well last year I told my dad not to wait on my and I hung out part of the afternoon and drank a couple of beers. So I would be happy to hang out while waiting on a driver since I have something else to occupy my time!
The first time I rode the HHH 100, back in 2011, I planned to camp, but it was so hot my buddy and I changed our minds. We drove around and finally found a vacancy at a Motel 6. There were record heat temps that year.
I plan to ride in 2014 - will probably go with a host family.