After watching it a couple of times, I'm calling fake too.
No snow on front tire, and a couple of those uphills would not be navigable even with studded tires.
I've ridden dirt bikes in deep snow with studded tires. They get stuck pretty frequently on level ground, forget uphills like that.
His helmet never moved, no matter what was happening with the bike. I have no idea how it was done, but I have my doubts.