When hosting this locally, I don’t see how 200 GB is much of an issue. Storage is so cheap these days, if you want to host it locally, just buy a 256 GB SSD just for that data for $20. Anyway, you were asking for a mirror, to which I replied with the information about the ZIM files. I don’t really understand the issue. Stackoverflow just isn’t that small, there is not much you can do about that.
I think it’d take a few hours to setup even a smaller copy of SO, which isn’t ideal for answering a quick question.
The download? Maybe, depends on your Internet connection’s speed. Actually serving it as a website certainly doesn’t take hours. It is rather a matter of seconds.
WTF?