From your list I have kniphofia, crocosmia and beautyberry plus other things on my list that you may check out. If you find anything of interest, I would love your clematis.

Yes, not the type of clematis suitable for growing in a container, especially if you want it to climb into a fir tree. It could be done but only if periodic root pruning were undertaken - in effect bonsaiing the vine and reducing its ability to climb unhindered. And I'd opt for something the size of a half whiskey barrel minimum for a clematis this robust.

Yeah, baby, YEAH! Go, clem, go! I had a montana when I lived in Knoxville, but I didn't have it for enough years for it to get really big. I FINALLY planted a new one here earlier this spring -- should have done it years ago. As long as it agrees to grow the direction I want it to (crossing fingers!) it can eat about 40 feet of fence and then a row of cedar trees and I'll be ecstatic about it. Here's hoping!

Yes, my research indicated 'Wilsonii' blooms a couple of weeks later than the pink C. montanas. Which is right about now. Also pictures of 'Wilsonii' show pointed flower petals like my vine, plus pale chartreuse center stamens. Also mention of a 'chocolate' scent. My vine hits all those high notes, which is why I think it might be 'Wilsonii'. It isn't C. grandiflora because those flowers have rounded petal ends. Quite different to the pointed ends shown above. I'm going to post a couple more pictures as to what the vine looks like. You guys have been great with your suggestions! You've already convinced me that perhaps cutting things off at the base is not a good idea. But check out these pictures and tell me what you think. These two pictures show the birds nest of non green vines, as of today. This is the base. Also extends behind the tree stump. Very close to bamboo as shown.Again, back part all tangled vines. No way can this be pruned that I can envision. Front part has the green and flowers. It extends to a trellis on left. Here's a wide view of C. montana with another clematis also flowering as of today.