I remember my brother bought a Vampire PC game some years ago. At the time we where still stuck with our old, suck... not too developed computer, so he couldn't install it. He described the space required for the minimum installation though, I think it was around 700 mb, which at the time was pretty big. I wonder what happened to that copy. He never installed it on oner of our computers though, that's for shure...
Übereil
Sounds about the size of probably what Vampire: The Masquerade by Nihilistic was, from reviews I've read.
That was party-based, if I recall. Wasn't a great game, I heard -- but for its time, graphics were good.