If I remember right, the biggest partition you can use with DOS is 2 GB. I'm not sure if there are limits to how many partitions you can have, but 80 GB seems like overkill. Given with the way this is set up, ripping CD-based games to HD seems unproductive, given the fact that only 5-10 will fit on a partition.

I'm thinking that alternative DOS shells like 4DOS or FreeDOS or DrDOS may offer more flexibility with assigning partitions but I don't know for a fact (plus, you said that you wanted to stick with 6.22).