I went within a whisker of being spooled on an 18000 spool with PE10 Varivas on it a few months back. I think I had about twenty to thirty metres left on the spool at one stage. Say you have a cast 80m away. A decent NC GT can easily take 100m in a single run. Another short run leaves you with very little to play with.
Still, locations like NC where fish will run so far are quite rare. If you're fishing most locations with Nomad, you'll be dead long before then.
In terms of snap offs, it really only becomes a problem if you have a snap off at the spool. If this happens, that spool is buggered. The other thing that can use up a lot of line is if you tie those huge bimimi loops for your twisted leaders by using your knees to spread the loop. If you do this currently, learn to tie a small bimimi loop with your finger.