You don't HAVE to brumate to have successful breeding, just so you know. As to your question, I would suggest waiting till next spring at this point, but it's ultimately up to you. At 2 years, he could be old enough, but might be better off giving him a little more time to get ready (as well as the quarantine period). Especially if the female is much bigger. Won't always stop the guys, but some can be a little intimdated by a significantly larger female.