Good job, never mind the OF, much less the pacemaker! Here are my Scientific Wild-@ss Guesses on your questions.
Well, if your weather was like ours, today, the heat and humidity probably contributed to the cramps. Since you've covered the hydration aspects, you might check the nutritional stand-point. Potassium, calcium and magnesium are usually recommended. Potassium and sodium are supposed to be in some proportion (that I don't know) in the body. Sodium is in everything (salt). Potassium is harder. People usually recommend bananas. Most dairy stuff is a source of calcium, some people take Tums. Not sure about magnesium, leafy vegetables?
I don't think you rode too little this week... with 1200 miles in your legs, it probably wouldn't have hurt to have ridden a little less, particularly last Sunday, but you were probably pretty well recoved by Saturday. 20 miles 2 days before is about right, IMO, provided you don't push it too much.
Another possibility is that with the climbs and the motivation of all the other riders, you rode a harder pace than you're used to... in my opinion, it doesn't matter how well hydrated or nutrified you are. A good (too good?) workout can still cause cramps!
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Hey! I may have to have my lawyers talk to you about your handle... copyright infringement!
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