Thanks for all the helpful replies! I was cold crashing to get the remaining yeast to drop, not to stop fermentation. This is the first time I've made something from unfiltered juice and didn't trust that I'd know when the yeast had all dropped. But since I didn't test OG and just guessed that the fermentation was pretty much done I'll probably add airlocks for the first couple of months just to be on the safe side.
My primary concern was oxidation. I bought the growlers from a local brew pub and had to return one that had been sitting in their display because it had turned. But it sounds like with the cider, as long as I practice proper sanitation, it should be fine, yeah?
Thanks again!
P.S. @Two0Fish, I knew to call it ciser but thought, if I did so, some forum rule would make my question more appropriate in the mead forum, and then I thought I'd miss out on teh great wisdomz of the cider heads here. I was probably overanalyzing.