the best "group" to join is a small quiet town, well away from large population centers, far from any major highways, off the beaten path.

one that is well established with people having a balanced diversity of useful basic skills. ie: doctors, dentists, blacksmiths, mechanics, machinists, farmers, ranchers, animal vets, plumbers, carpenters, welders, gardeners, hunters, et al.

a place not dependent on a limited number of employers, or having undesirable features (like a nuclear plant, or oil refinery, or large hazard waste recycling operation, or in a flood plain, or tornado path...)

then move there so if/when problems arise you have lived "within" for a while (unlike just owning a vacation home there), so you know the people, fit in, are a valued member of the community, are accepted and can contribute, where your skills are important and can be traded with others.

this sort of place is easy to imagine, just think of a smaller community 100-plus years ago. the hard part is finding such a place these days, but they do exist.

moving to a small rural town may be one of the best options, the bigger problem is the commitment it takes to totally change one's lifestyle to move to such a place. few are capable of doing it.