I did RAIN in 2006. The first 90 miles were pretty nice. The last 70 were a nightmare. I and my group thought we were prepared. We had done enough 140 mile training rides to get our food and water needs sorted out but that 102 degree weather was so brutal it threw us for a loop. By the last 30 miles I had run out of gas and I had to average 15 mph to make the cutoff. I made it with ten minutes to spare.
I learned a few hard lessons and we may do it again this summer with a few changes in place.