Judith--I had a similar situation last winter. I allowed the newly potted plant to get a bit of winter exposure outside, then in January I brought it inside into a cool greenhouse where I overwinter some tender potted camellias--had to dig through about 4' of snow to get to the daylily pot! It sprang into life after a couple of weeks with the warmer temperatures and supplemented light. Come April, it went into the ground and did just fine this summer.

I'll be doing the same thing again this year with a group of seedlings that grew in pots all summer (it got HOT very early this year and I just couldn't find the energy to plant them). No worries.

Hope that helps.

-eric

Eric.....thanks so much for your reply. I think what you are saying is that its good for the lilies to get a bit of winter first - then protect them with the greenhouse. We should be getting our first frost but doesnt look like anytime soon - it was in the 70's today. The lily is growing well - guess I will let it stay where it is until we get into the really miserable weather that comes with January.
Judith