You certainly can move it. Prepare the planting hole in advance to lessen your own stress and add manure, bone meal and compost. When you're done planting please use mulch on top - 2" is fine.
Moving it while it's still attached to the trellis will be a major juggling act so if it becomes too awkward or too difficult feel free to cut it back. No harm will come to the clematis. Give it a big drink of Epsom Salt - 1 tablespoon to a gallon of lukewarm water, and it should send up new sprouts shortly (within a few weeks).
Please let us know how it worked out for you.
