I applied two years in a row; first year I heard back during the October half term, and the other time I heard back in January.
And if helps you analyse it, I got in both times, second time with a lower offer. I know this sounds stupid, but STOP WORRYING. If you're in, you'll be in. And if you aren't, then you won't be. The length of time they take to get back to you is completely beside the point.