Basically, with 3D printers and solar power and local grids and machine shops to fabricate for local needs, and a loose mesh network to connect these decentralized nodes/communities together (like Mastodon, instead of the paper-and-print Amish newspapers that exist). A kind of techno-libertarian-Amish blend, to form a society that was more resilient and modular, rather than hyper-centralized, dense, and easily swayed by viral influence/behavior/trends or literal biological viruses.
EDIT: Of course it would never "scale" since such a system probably could not support higher population levels at all, but maybe that's okay in the ultra-long-run or some post-apocalyptic rebuilding future (also dangerously veering into population control and genocide-ish topics).