The first key to survival is to be out of the way of the ‘hordes’ Far enough out of the way so that their foraging in the urban and suburban areas disperses them.
Second is low profile.
These ‘hordes’ won’t be the “Walking Dead” type who can walk and exist on nothing for decades; they’re still human (at least by some standards) and vulnerable to all sorts of calamity, fighting amongst themselves, for instance.
I expect internal casualties amongst looter types to be 80% or greater.
And very quickly. Within the first ten days to two weeks.
The 'hordes' can't go too far from their supply of crack and heroine.
Plus they’re lazier n’ crap. They’re more enclined to sit on their front stoops with their hands out, than walking 15-20 miles to the next town to loot.
Barely any more evolved than territorial pack animals.
I’m really not worried about hordes from the city. My guess is that the biggest problem in a SHTFC situation will be my own neighbors.