Sorry, didnt read your post propperly

Yeah, id partition it off. Another thing you could do is create 3 partitions. 1 for the basic os, 1 for programs, 1 for samples and storage. This means you can do a full os reinstall and know you wont lose any data. Check how much room all your samples and stuff take up at the moment and then make a guess on how much more space you will need in that partition in the near future, then partition it acordingly.