Even though we're in the same zone I'm in Tennessee and your in New York I can leave mine out all winter. But if I had to dig mine up I would wait till thay are completely brown. they still bloom if we have a couple of weeks of warm weather. Mine were blooming up to this past weekend when a hard freeze killed them. And that sounds like a good way to store them in a brown paper bag and some dried peat moss in your basement. Or if you could just carry the whole pot in your basement leave them in your pot. Let it dry out. You don't want them to rot. Hope that helps.
