Well, mine is still in a heeled in pot so I cannot make any suggestions, but Rouge mentioned his on the linked thread and he might have suggestions if you send him here.

https://www.gardenweb.com/discussions/5738635/clematis-season-2019#n=19

What's it like when it's fully settled in?

Very vigorous and very floriferous!

In fact I am trying to find a bigger support to accommodate its growth. I put two 6 foot obelisks next to each other and still it flops over onto itself :(.

(The last two years it has exhibited clematis "wilt", luckily after most of the flowering has happened. but I am wondering if it doesn't help that it is just too 'cramped' for its location...not sure.)

Rouge, it typically isn’t wilt with type 3s like Tie Dye. It is damage or lack of water, and you can whack it back hard as the flowers, and in some areas many of the vigorous type 3s will rebloom before season’s end.

It definitely isn't due to a lack of water and damage would likely be represented by browning and dying for only part of the plant. And complete "crash" has occurred in multiple years.