I carry one of those SOL things, or something like it. Strikes me as an appropriate name, but I've never used it. We usually have a bunch of layers with us (insulation, rain gear). That stuff is so light now that it just makes sense, and I could likely survive pretty cold temps with it overnight, but I hope I don't have to.
That being said, plan A is still to get back to whatever camp, and sleep in a tent. Headlamp and a backup light are easy to justify, especially if you've been without one. I carry firestarters (VSC), but have never had to use it in a real emergency. Fire is frequently impractical in sheep country, although moose country usually has lots of good wood.
I'm planning to sew up some silnylon tarps this winter, and will probably add one of those to my "always in the pack" list.
