This was my first Winter BagBash, and it wasn't too hard to earn 11 hats.
That being said, new users like me are unlikely to earn hats that require large amounts of reputation or very high-scoring posts. For example, the Scarf Ace hat requires an accepted answer with a score of 40 or more! Not that the hurdle stops me from trying. ;-) In fact, it's giving me a chance to have fun while aiming high!