Clematis: Help before I rip them all out!, 1 by Dimmer

Dimmer wrote:
Hey all I just brought a house this spring and I do have a clematis and all kind of other plants . The clematis was growing very good than it and than it got very heavy and is now fallind down and dying I have read that you cut them down i that in the fall or is Aug to soon. I never had one before and I want to get more. How far can you cut them down too. Thanks for reading. Here is a picture from a month ago
Dimmer(AKA) Kim