If the internet would go offline "for real" even for days, all hell would break lose. It would not be as bad as electricity going offline, but it's in the same category now. No credit card payments payments (food, gas), no logistics. Prepper stuff.

The real scenario long-term is that quality content like Wikipedia could either be taken offline, be poisoned by AI or taken over or censored by authoritarians or corporations or interest groups. Like social media and parts of the normal internet already.

So archiving is good anyways.

To your actual question - quality non-fiction e-books would be valuable. Wikipedia is a superficial skimming of human knowledge, lots of the real stuff is in books (think medicine, agriculture, algorithms, engineering etc.).

Practically, a home WIFI has a very limited range, so just handing out sheets with instructions to your neighbors would work. And for a wider mesh network, you'd need to make do with whatever evolves in that scenario.