I have absolutely no access to the back end of the wiki to check total storage space. However, I can see
this page and do some math and estimating.
I checked 101 random articles and came up with an average content size of 5.5 KB per article. However, there's also roughly 19 KB of additional HTML coding embedded within each article. Using that total for each of the 10,044 content pages, you get ~236 MB worth of actual text. This doesn't include the 46,800 redirect, talk, and other pages that can't be easily summarized.
There's no easy way to get samples of the uploaded files, but I think it's safe to assume an average size of 100 KB per file. Some files are far larger than that, but most should be much smaller. That means the 20,000 uploaded files would take up ~1,923 MB. Put them all together, and everything should fit comfortably on one DVD with under 3 GB of total content. However, I assume you'd also likely need to have MediaWiki software on your computer in order for the links and content to work properly.
Of course, these estimates could be completely wrong, so I'm curious how close I actually am.