I've yet to figure out why it's considered necessary to switch to dpns on a hat. Maybe because I only use longer cables or can switch to a longer cable easily, but I just loop the cable once or twice and keep on knitting with the circs. I've gone down to 8 sts on circs. I guess if you're using fixed circs and don't have a long one in the same needle size it makes sense to need dpns. OK, maybe I just figured it out. Thanks for letting me *think out loud*.
I should never overestimate my basic arithmetic skills.