: Anybody have thoughts? If you were on a long distance trip and
: packing light, what boat would you build?

I'd build a sailboat, or a row boat, or a canoe, or a raft and then, maybe, a kayak. In that order of preference. I know that doesn't answer any question about long v short hulls, but I do, actually, have a point. And that is - for me - sitting in a kayak becomes unpleasant after a few hours, and downright torturous after many. On long river trips, I have found that I want to change position - often! I want to be able stretch out, sit up, lay down, sit cross legged, etc etc. All of that can be done in those other boats - but not really in a kayak.
Being confined to basically one position for long periods was/is a common method of torture . . . .
As for the sailboat, I'm referring to a small "sail and oar" boat, which could be rowed as well. On long trips, taking advantage of the wind is just a no brainer. If human power only is the goal, I'd still opt for a rowboat or canoe over a kayak.

If I had to take a kayak, I doubt that length would matter a whole lot, and comfort would matter a lot. One of Harvey Golden's
replica Bering strait, Chugach or Yukon Delta kayaks/baidarkas might be just the ticket - lots of room for gear and to move around in. You can even put a sail on them....

Here's the sort of thing I mean