This summer I have gone from 32L pannier set to a 67L pannier set. Man, they are big! I have not added more stuff, in fact I have shed the cook kit and dehydrated food. When I open a pannier, now I can see everything in the bag all at a glance as nothing is layered, everything is set "on end" in one layer making it easy to see everything without having to forage thru the bag.
Of course, the weak will pile in more stuff because they can! Each bag has two outside pockets, and only one on each bag is being utilized. Without self-control I am certain things could get out of hand.