I'm what you might call "Grimpeur-curious" and, if the new cassette turns up in time, intend to have a crack at the AAA Milne as a DIY in September. I may even try it with the gearing as is. It has got me up Duncton, the north side, with a gear to spare after 80km and Ditchling too, in recent weeks, but the idea of trying 100km in the Surrey Hills, local to me on 36 x 28 makes my knees knock.
You may find my corpse by the side of a hillside road as a result but all good practise for next season I reckon.
But can someone give me a summary of what the "Grimpeurs du Sud is about"? Googling seems to lead to various dead-ends.