For the longer-term scenarios I look more to knowledge and tools than to pre-fab'd answers. For example in shelter I know how to build a debris hut and would if I needed.

For a short-term (3 days to a 3 weeks) scenario but in order to avoid that eventually I always have a number of tarp like expedients. Silnylon poncho - tarp 5X8 foot, large garbage bag, plastic poncho, space blanket etc. I don't want to spend too much time or energy building shelter in a short term emergency. I expect my energies will be more crucially needed for medical / navigational / traveling speed and taking the time to have to construct shelter each night would be a trouble.

For the medium term (3 weeks to 3 months) I count on these tarplike expedients also since they would be adequate tho not luxurios. Tho in these scenarios I may build a "base camp" site I still would need my energies more likely for other things such as food gathering and water prep. and community re-building and disaster relief

For longer term (3 months and beyond) I count on tools like, minimally, Ax, Bow-Saw, Sledge, Shovel, Anvil, File, Rasp, Mallet, and Hammer to construct shelter that is solid enough that I don't have to maintain it structurally after it is built. These long term scenarios are ruled "off-topic" by the definition of this site tho so I won't go deeper than this on them.