I always have issues with keeping outdoor plants indoors, except for the very shortest amount of time. Clematis can tolerate freezing temperatures easily but any green growth you see now can certainly be damaged by freezing weather. Not to worry - it will come back at the appropriate time.

In my zone 8 climate, we can plant whenever soil conditions allow - that means as long as the soil is unfrozen (soil never freezes significantly in zone 8) and not overly saturated with winter rains. Leaving the clematis in their nursery containers outdoors could expose the roots to unnecessary and potentially harmful cold but planting them in the ground will alleviate that possibility. At the very least, you can sink the plant container and all below the soil surface until you can comfortably plant.

Thank you, gardengal. I have already put it out as suggested. Hoping for a great Spring!