My wife and I have done several 60+ mile rides this spring and the climbing involved in the GWBR 100K might have been a bit more than what we've done this year, but hydration and electrolytes aside I don't think I'm handling short steep roller well, often putting us in the wrong gear. Given a "real" hill we put things in a low gear and grind away as necessary. Big rollers you build up speed, milk the speed on the way up and try to get things in the right gear, but these short rollers find me bungling the chainring selection and once really under load it can be hard to change from our "36" to "24" (18 to 12 on our daVinci). In any event definitely a learning experience. I haven't had cramps like that since I rowed in college about 100 years ago. I am going to try Endurolytes as a change of pace from Nuun and might also go with a Camelbak, but I think I was reasonably hydrated.
The cold gatorade was my beloved stoker's idea although I prophetically protested mildly claiming I would cramp up (which I did). We also passed a bicyclist at the side of the road who had broken his 10 spd chain; I only had quick links for the DV's 9-spd drive train, but at stoker's urging circled back to see if we could help (and cramped). Of course the stoker is never wrong
If I had been clear-headed I would have taken out my chain tool and nitrile gloves, but the pain dulled my reasoning.