I know this is coming too late for hurricane protection but there is no issue with cutting back your clematis now (or last week :-)). If you brought it in for protection, I'd be inclined to keep it in, providing "in" means a non-heated or very cool area. You do not want to encourage the plant out of dormancy which excessive heat may do but you also do not want the soil in the container to freeze solid. Storing somewhere that remains around 35-40F is just about ideal.

Tx gardengal. I thought clematis was ok in a pot in zone 6, no? I planned to keep it outside all winter...I don't have any other option, besides keeping it inside my apartment. I don't have hot steam heat or anything but still....obviously my apartment will be anywhere from 60-70 degrees inside during the winter...

Sorry for delay again but don't have access to computer on a daily basis :-)

No doubt the topgrowth of the vine would be fine in zone 6.....it is just the root system I'd be concerned about. Roots are much more vulnerable to cold damage. If the plant is in the ground, it is not really an issue as the surrounding soil mass is adequate insulation. But the roots in a container don't have that benefit. And sometimes (maybe often), the roots actually come into contact with the container wall and almost direct exposure to cold air temperatures.

You could keep the pot outdoors but you will need to provide some additional protection. If you can slip the clematis container inside a larger container and then stuff the open space with crumpled newspaper or what have you, that should help. Or wrap with bubble wrap. If the temps look like they will drop into the low 20's (really anything below 25F) for any length of time, you may want to bring the container indoors. Just get it back out as soon as possible.