Yeah, the projects I've heard about that have done something like this broke it into multiples.

For example, 1000GB could be broken into forty 25GB torrents and within that, you can tell the client to only download some of the files.

At scale, a webpage can show the seed/leach numbers and averages foe each torrent over a time period to give an idea of what is well mirrored and what people can shore up. You could also change which torrent is shown as the top download when people go to the contributor page and say they want to help host it ensuring a better distribution.