Got my first kayak of my own last year, a 12.5L Stratos Dagger. Thought I was getting the S, but they gave me the L and didn't actually have the S in stock. I have done plenty single day trips that were multiple hours on rivers, but never an overnight trip.

Two trips planned, first is 3 days with two days of paddling, the second is 1.5 months later and is 7 days/6 days paddling. These are group trips with campsites and bus support to and from put-in/pull-out. Just don't know what I don't know!