I'd just wait until they do go dormant and cut them back then. You won't have to go through the process multiple times :-) I can't imagine too many types of clematis are pushing much growth at this time of year anyway. Even in my very mild climate (with a couple of blooms still present), the leaves are starting to yellow and fade on all the deciduous vines.

Is there a reason to wait until spring to plant? Unless you are in a really cold zone, they should settle in well at this point and will be ready to take off in the spring with their roots already settled in.

Hi I am redoing massive amounts of my gardens and need to find more supports for the clems to grow up. I have them in huge pots in good soil and the are putting on a lot of new growth now. Thanks for your input. I am in Atlanta and today will be the 1st day in long time that we wont hit the mid 80's