It passes. I've been commuting with this hub since late summer, and just waiting to see how it works in the cold. This morning it was -17c, the coldest it's been so far. It spent the night in our un heated garage, so it's not like it was warm to start with.
To be honest, it performed as always. seemed to be totally unaffected. If I could work out the logistics, I wouldn't mind taking all my gearhub bikes up to the NWT with me later this month when I go up there to work for a couple of months. I'd like to see how they work at -40.