I'll add a few things. I did it in 2008.
Indysteel said, "Mr. Silver and I are lucky in that we enjoyed some decent weather the years we've done RAIN."
that would be true if you consider riding for 50 miles in a constant hard downpour and lightning decent weather.
but at least it kept us cool.
I would say that if you could continue the kind of riding that you are doing and add at least one really long ride a month that you will be doing good! by really long ride, I'd say add 10 to 15 miles longer than what you had previously done. I know it would be a drive for you, but you'd be welcome to come to evansville just about anytime and we'd take you for a longer ride, whatever distance you needed.
I would recommend at least one ride longer than 100 (like 120?) prior to RAIN. And possibly back to back long rides. The Horsey Hundred is an excellent training ride for RAIN. Usually around Memorial Day in Geargetown KY. First day is around 107 and second day is around 80.
Also, we did not have a dedicated SAG, but we had two Back up people to call if we had an emergency. We did fine.
A couple of small problems I had.....one of my bottles popped out during the hard rain and I didn't know it. So I only had one bottle. the stops are far enough apart that I felt that I needed two filled bottles at all times. So I eventually stopped at a gas station and bought a gatorade bottle That fit in the water bottle holder. Also, the first stop was way too far for me. I needed to eat earlier. So I had some things to eat with me, things that I could eat without stopping. But with the rain everything got a bit soggy (and this is even though all was protected)
a couple of other things I would do next time. Even though I didn't have a dedicated SAG, I did see my back up SAGs at a couple of the stops. I would have them stash some dry colthes (especiatlly socks) to change into, either for rain or sweat. I'd also stash an extra water bottle with them.
"Being retired from Biking...isn't that kinda like being retired from recess?" Stephen Colbert asked of Lance Armstrong