Avalanche is a trailing/scrambling non clinging climber. The secret is to plant deeper then the top so it can shoot from below ground and this helps to avoid Clematis wilt, if you did this cut it down to below any dry or wilting stems mulch well and leave alone and it should be ok. Also the roots should be in shade if there is no foliage cover to start off.

That is one of my favourite clematis (would be perfect if the flowers weren't quite so big).
It's a "Group One" clem - if it was in good health it would be a bit late for pruning without risking next year's flowers. But take a look at http://www.theplantman.net/Evergreen-Clematis or the RHS page https://www.rhs.org.uk/advice/profile?pid=344 - particularly the "initial pruning" section. You may lose a lot of flowers next year but treating it as if you had just planted it might be your best option. And remember to water it!

Thanks,
Hopefully it will recover when it gets a bit cooler. It's an expensive plant to lose.

I dont think you will lose it they can behave oddly the first few years and eventually they do grow well.