Have you considered using a tall obelisk set over Nelly on her spiral? That way you wouldn't need to detatch her, but could just let her grow further, up onto the obelisk. She has the potential to get quite large, 2-4 meters according to Clematis on the Web.

Yes, I had that exact same idea. But the obelisks I've looked at online are pretty expensive. They are metal. The wooden ones seem like they block out a lot of light and are too "in your face". I want the clematis to be the star. Also, since I live in a co-op, I don't want anything too obvious like a wooden obelisk, because the mgt. might give me grief about that. You know, conformity, conformity, conformity. The manager already last year started to open his mouth to me about my garden, but I closed his mouth mighty fast by pointing out that my beautiful garden adds to the value of the property and that I receive compliments from everyone who walks by. Yup, that shut him up. If I can find a good deal on a tall obelisk (How tall should it be? More than 6 feet, for sure), I will bring it home.

I looked and looked on the interwebs for an obelisk for Nelly M., but they were either hideous or hideously expensive. I actually found a nice wrought iron 80" trellis for her at Home Depot. I pushed the 2 support prongs into the ground and used plant tie tape to fasten as many holdfast tendrils to the new trellis as I could. Thus more spread out, Nelly M. looked much nicer, even without any flowers yet. I think she will enjoy getting more sunshine on her leaves, as they are now more spread out and not shadowing each other, and they are now raised higher than the old support pole. Next year, when the vine is dormant, I will trim it off the old support pole. When the new growth appears, I will fasten it (if necessary) to the new trellis.

That's great!

Hobby Lobby - if you have one in your area - has some lovely obelisks and trellises, not that expensive esp. when you find them 50% off. Lots to choose from now.