At this stage you're unlikely to find any vacant accommodation in Byron for NYE. Call the Byron Bay Visitor Center http://www.visitbyronbay.com/ and ask them if they know of any place still open.
There is a lot of live music in town over NYE, good food and big crowds of young locals and backpackers. Don't go if you're looking for a quiet time. But it's also a pretty safe place to be too, and the weather is usually good. almost 10 years ago