Yup, Copplestone Yetis. Mark was cool enough to allow his yetis to stand in as snow trolls in the book - and darn good ones they make as well! (And super mega-cool to actually sculpt some figures for the game!).
I have a feeling the scenario is rather over-weighted against the high-level wizard, but, as I said, I haven't actually played it. So, anyone who wants to risk taking on the trolls, let me know how you get on!