I plan on doing some overnighters as soon as the weather warms up. I've been looking at the Axion waterproof panniers. They sell a medium - 1500 cu. in. and a large - 2000cu. in.
Although I won't be carrying a lot of stuff for a 2 or 3 day trip, I was thinking of getting the large panniers. I figure it's better to have them too big rather than too small. And maybe I could get everything in them, including my sleeping bag and tent.
Anyone have any words or wisdom about this?