I was about to start my own thread about a survival .22LR pistol, good thing I did a search first. Like the OP, my go to "survival" gun is a Marlin Papoose, and I had similar pistol criteria--light and compact but accurate enough to ruin a bunny or squirrel's day.
One thing I've noticed when kicking around options for this is that size and weight don't necessarily correspond to each other. A Ruger SR22 is actually lighters than many smaller guns, for example--bulky but not heavy. So that is a trade-off to consider.
I was also thinking that easy single-shot loading of subsonic rounds or rimfire shotshells might be useful, even when those rounds won't cycle the action. That suggests a Beretta/Taurus tip-up design, but neither company makes the longer-barreled versions of those guns anymore, though I might find one used.
Here's an idea--does anyone make a little tip-up single-shot pistol anymore, something like the old Stevens pocket and target pistols? A modern version ought to be very inexpensive and, I think, would find a ready market for plinking, target shooting and hunting/survival. Interchangeble grips, barrels in varying lengths and calibers, barrel-mounted sights or scope rails would all be easy to arrange and allow folk to dial in what they want. Perhaps we can get Chiappa arms to come up with a "Little Badger" pistol?
Cheers,
Matthew