If you planted the clematis deeper in the ground than it was in its container, then you likely didn't jerk the crown out of the ground. You should be able to tell if you did get the crown out of the soil and just replant it if you did. If you didn't, then the plant will just have already had its winter haircut.

Generally speaking you want softwood material to try and root from cuttings. Cooler temps. generally are best for root development so cooler but not cold would be best. You aren't wasting your time if you get cuttings to root from the material you did manage to pull off. Following is a link to an article on cuttings from clematis from the International Clematis Society.

Read it, take a deep breath, and relax. Should the plant not make it, you can always start fresh in the spring!

Here is a link that might be useful: Clematis from cuttings

My Lawn guys decided to be overtly nice and attempt to weed my gardens..they mistakenly yanked 5 of my clematis...you could have heard me screaming a mile away when I saw them on the pile of weeds!!..I thought they were gonners..but they have all came back up and are blooming..whew...so keep the faith....Jeanne