Clark has just shared this on his FB page :
https://www.wetransfer.com/downloads/c607710dbd45b3fa366fafedf0b49c2b20150127142355/e56b58
Can't check it right now since I'm at work but I guess from the "Winter Boots (Part 1)" title that it's an alternate version of "Winter Linn". Maybe the one from his BBC session ?