I am mildly surprised it made it up to the pass, considering what I have read of its abilities in respectable magazines.
There is something to say for a small footprint and a short, I assume, wheelbase. The old Foresters used to surprise a lot of people even with just open diffs and no traction control at all. But small and short wheelbase allows them to squeeze between and around things. Lifting wheels and spinning is a non-issue with AWD cars in my Subaru experience, except when climbing or going through stuff of course. But no problem with stability or breakage.
Still, with no power and pseudo low range, did it get pushed up to the pass? It is not that steep but the elevation is serious. I am not surprised the video does not seem to show any of the climb, it must have been a spectacle!