Looks like a neat route! Make sure you have lots of water with you.

Perhaps , since it's so remote, the brevet organizers might have a roving SAG with water, but don't assume it. It might be good to email the organizer and ask if there will be any sort of support provided. (Or it might actually say on the brevet info, I didn't look - still, would be good to double check w the origanizer).