I have not planned for a complete breakdown of society because I do not view that as being sufficiently likely to happen that it is worth the opportunity cost of planning for it. I prepare for things that I think are reasonably likely to happen (currently a very fuzzy assessment.) So far that includes:
1. Backed-up data including scans of vital documents in case of disk crash/break-in/fire/etc.
2. Basic necessities bag (essentially, several days of clothing/toiletries, cash, spare credit card, vital docs, etc.) in case I have to grab something on the way out the door when the apartment is on fire.
3. Having ~2 weeks of water, food, fuel, lighting in case of an earthquake/other disaster significant enough to cause loss of services for a lengthy period of time.
I also have lots of camping/backpacking supplies, firearms, ammo etc. on hand, but they were not purchased as disaster preparedness items. I am also a dual citizen and my overseas half of the family does a pretty balanced mix of farming (gardening, chickens, sheep, deer, lobster & some lumber; the fishing is also pretty good there) so if it were a slow collapse I guess I could go there.
