I saw an article today about an organization in Seoul (and Palo Alto) called Flash Drives for Freedom. The gist is that they smuggle donated flash drives into North Korea loaded with information that is censored by Dear Leader. One of the content items they mentioned was a Korean version of Wikipedia. I thought, that fits on a flash drive? Turns out, the English version, just the articles without the pictures, clocks in at 15 gigabytes compressed. Text compresses well, so that's feasible. I assumed that Wikipedia had grown much larger than that, or I just never really thought about it.
Anyway, you can get your own copy of Wikipedia here: https://archive.org/details/Xowa_enwiki_latest
I haven't decided if it's useful to actually have a copy on my hard drive, but I did find the possibility interesting.