I did supported RP (sub-100hr, actually 62hr) in 1989 (age 42) without mudguards and on 36/24 min gear. Support meant spare (dry) clothing available if needed (first, western end day wet), gears meant hardship, so triple better for tired body.
Reason for no m/gs also around total bike/body weight. Everything is going up a long way and if supported ride much more freedom. Much warmer in summer, when you should be able to dry out or suffer a bit of damp with wet weather gear. You do not find the locals using m/gs.
I have done several sportifs in Pyrenees/Alps and find 30/26 a good all-round low, though lower touring triple could give 24-26 lowest. A lot depends on your age and strength but whatever you ride comfortably on for AAA routes in UK should be OK in Pyrenees. You will need to find out by riding a 200AAA route to simulate end-of-day fatigue.
SteveP
BC Club Coach
ABCC Coach