even compressing all of the files is going to require around 200 gigs for a game like Kotor
Uh, probably not. If you've ever ripped a DVD to hard drive it doesn't take up 400gb, and I doubt a KotOR 'movie' would need to be as long as a full-length feature film.
If you compress the video as you go you'll probably need maybe 5-10 gigs of free space, including bumper space for the uncompressed video as you film it (before compressing). Suggesting you need 200-400 gigs is ridiculous, though. I've filmed plenty
of things, some as long as 30 mins, and my hard drive is only 80 gigs (and I didn't compress as I went).