Arioch's collection sounds like the one I got off Van Meuwen recently. Only a few weeks back in fact. Mine are potted up at the minute just and appear to be surviviing if not developing, but thats not a concern.
I'm with Dave Morgan here on putting the pots under soil - this worked a treat for me last year and jave most of my left over perrennials in pots again this winter. I also bought a couple of plastic corragated panels to keep the frost off - last year I made a wooden frame and put plastic sheeting on it which did the job but didn't like the weight of rainwater.