Those of us in the south with survive a collapse just fine, I hear that kudzu is edible :-(
File this away for future reference and hope you never need it, lol:
http://www.eattheweeds.com/kudzu-pueraria-montana-var-lobata-fried-2/
It’s actually a very useful, versatile plant, just don’t let it take root anywhere on your property, it grows a foot a day. I’ve watched an old rental house not too far away sit unoccupied for a couple of years awaiting destruction for a road widening, and it’s almost covered now, just a green vaguely house-shaped lump with a few peeks of siding or roof in the summer.