I stopped watering in August while they were still in their pots and waited for the leaves to wilt and go yellow, then I cut them off, I just put them to rest a couple of weeks ago, it's amazing how they can keep growing without any water for so long. I left them in the pots last year and this year.
Now that you explained about the frost and all, I think you can store them now, keep them from touching so that the air can circulate around them. Where will they be stored, is it dark? Mine are in a cool dark cabinet, I check on them once in awhile to make sure there is no rot or mold going on.
