Norwegians have typically a rather triangularish head and face, So it stands between a Mco-look alike - whom have typically a quadratish muzzle, and the Siberian look alike, with its more rounded muzzle...
All three breeds are biggish,
Here Im mostly thinking on Siberian, they can get really furry in the winter.
Usually, I'd just say he's a domestic long hair and leave it at that. A lot of people think their cats look like a Maine Coon, Siberian etc and it's easy to say I don't see anything specific that points in that direction.
However, your boy has quite an impressive mane and tail and more so, his muzzle has the boxy, pronounced look that one sees in those breeds. His ear shape too is more what I'd expect from a cat with lineage.
Has he been neutered? He's really got that Tom cat look to him, and if he has been it leads me to consider even more that he could actually have a purebreed cat in his background - very near in fact. If not, his facial look could just be due to unchecked hormones lol. Either way, he's wonderful.