Wow these are excellent tips. Not sure what the turnout will be like. Good to know about not staying too long at rest breaks. For us there will be only one at the halfway point. How long is "too long" to stay?
@marni, I've never had the need for chamois butter. I've ridden 25 miles before without issue. I don't have any. I do have mountain bike shorts with a liner that has a chamois though.