If you really want to survive, first GTFO of the cities. Learn to grow your own food. Learn to live with out AC, TV, internet, etc. Get real paper books. Farming, medical, carpentry, etc. Dig a well, or at least have some sort of rain catchment. Learn how to cook over an open fire. Get some cast iron cookware. Get a .22 rifle (among other firearms). Get to know your neighbors. Get in shape now.
I've done all of that in a year an a half and I'm a cripple.
In your reality it takes 20 years to plant a garden and dig a well? Neat.
For those that don't have much going on today.
Bill Cooper in California The Porterville Presentation full
https://youtu.be/MAmShuanEBQ