IMO the best idea is to form a new (small) town and repel invaders.
But if the bigs (military) get involved, it might be best to be undeRGRönd and even more rural. Not literally underground, but well hidden. Absent that, one could watch the old Charlton Heston movie, OMEGA MAN for ideas about urban survival, or better yet, join SHTFSchool.com
But there is nothing like a movie to jog the imagination!
"ROGUE ELECTRICIAN" Hoping to be around to re-energize the New World.....
Cogito, ergo armatus sum