I'd bet that if you potted up your daylilies into 1 or 2 gallon containers (I'd go with 2 gallon myself for the depth) they would start to grow. I can't imagine you being cold enough to really set them into being dormant for any reason other than water and want of space. Stick the pots in the shallow part of your pond so that they are in 1-2 inches of water and they will likely take off. In your neck of the woods they would probably benefit from some afternoon shade as well.
