I finally got a break to print 16x20's from some of my summer 6x9 rollfilm back shots (ACROS - haven't printed any of the color ones yet). All from a long backpack in the mountains. So yeah, for me the smaller format is a bigger headache, but an inevitable one for a long trip, given the loss of Quickload sleeves. My success rate has climbed close to 100% with rollfim backs, rather than the 75% or so on the first trip I substituted these for
full 4x5. By this I mean obtaining a print very nearly equal to what I would expect from 4x5, though obviously not capable of quite as much sheer
enlargement. 16x20 is decent. I already have lots of 8x10 negs on hand suitable for big prints, and am still adding to those when my pack space is dedicated to primary photo gear rather than two or more weeks worth of food and camping gear. I also have a 6x9 rangefinder, along with a P67 system; but these obviously don't involve either view camera movement or the same kind of groundglass focusing. It's all fun; but one just has to learn the idiosyncrasies of each specific system. One really nice thing about the smaller format is that you get more "reach" with shorter lenses,
using less bellows extension. For those strenuous backpack trips I prefer to carry a little Ebony 4x5 folder rather than my bulkier, more convenient
Sinar. It will handle a 360 lens, but this involves racking out the front and back base tilts, and reveling the center pivots, in order to handle that kind
of focal length. But with 6x9, I substitute a tiny little 300 Nikkor M, which lets me bag those distant crags and details, using focus gearing alone,
much more conveniently.