Aconiteandy, I've propagated clematis from cuttings for quite a few years now, though by a different method from yours.

To carry first-year rooted cuttings through the winter I grow them under lights in my attached (south-facing, cool, but not freezing) greenhouse. They stay in their pots through the next fall; then spend their second winter in an outdoor cold frame: I sink the labeled pots into the ground and put on a heavy layer of mulch. The third year they go into the garden. I don't think you gain anything by planting them in the garden any earlier. I even repot bought plants, if they're small (3-4" pots). into 5-6" containers and let them spend at least their first winter in the cold frame.

Thanks Gary. I pretty much decided to leave them in the kitchen green house window for the winter. It just seemed that if the growth were all green and not hardened off it was taking a big big change putting it into the garden. The greenhouse window is very cool. Down to 50 at night and 60-65 during the day. The surface is granite and downright cold. So they should do well. Especially because I tend to keep my eyes on things growing there. (It's right in front of the kitchen sink.)
I hope I can get the things to bloom next summer as we are moving to Ecuador a year from this Nov. :)