I think the resilience of character, as well as having come from a background of austerity, aided those people in recovering. Rather than waiting around for an outside entity to do something, they have come together and did for themselves, improvising with what they have on hand.
In all of my studies, searching and reading of real survival situations around the world, the one thing that has always come to be to be the universal truth about who survives is one with determination, ingenuity and resolve to continue.
Human beings are very adaptable.
I often wonder how long those "chairborne commandos" who stockpile MREs and AR-15s will fare should their little bunker become destroyed as a result of natural or manmade disaster.
From my years of researching the topic, very few survival situations ever require more than a minimal use of firearms, especially against hostile humans. There are much more important factors to consider, such as proper sanitation and food procurement, processing and storage.
But above all, a close community, used to relying upon each other, is very hard to replace.