Clematis Wilt??

Hi. Almost sure I have the start of Clematis Wilt on my Nelly Moser but never had it before so need some advice please.
From photos you can see on some of the stems the tip is wilting and some of the leaves are staring to wilt from the top down. 3 stems out of 6 seem to be effected.
After about 18" (457 mm) the leaves seem ok. I have one leaf with 2 brown spots and one very small leaf that is half black. If it is indeed wilt what is the best couse to tack? Do I cut whole stem down or to just below the leaf wilt or all the way to bottom? Any other advice would be appreciated.

 

Wilt starts at the bottom and works up. Lack of water starts at the top. So check for damage at the base of the stems. Slugs and snails love Clematis shoots.

 

Lack of water was my first thought.

 

Thank you for your input. water well tonight.

 

Check for stem damage first.