My best advice would be to always kill groups of wolves or fenrings you see at night, the fenrings share spawn points with wolves so if you're running around killing all you see there's a chance a 2 star wolf spawns in their place on respawn. I just ran around an area where there were multiple spawn points wiping everything out and checking back in a few minutes, got a 2 star after a few nights with this strategy.

Another note would be to have a pit already dug out near the location you're checking for easy taming once you find one.

^ as said above, a pit is key. Capture a few 0 or 1 stars and when you get your 2 star, all is ready for breeding...and wolf skewers are tasty when camping. Skal!

Got lucky. In either the next night or the one after, I saw a pack of 3 wolves. I shot at the 1 star but accidentally hit the one behind it, a 2 star.. :O
There were two 1 star wolves, and a one 2 star wolf. I managed to imprison them together to add to numbers while not having to risk moving another wolf and dying in transport or for it to despawn.