If you back down the temps and light schedule then it is possible for your beardie to go out! I herd of 1 or 2 others beardies that did not! Good luck and just my 2cents!!
My two older dragons don't brumate. They just slow down and are up a shorter amount of time. I don't believe in forcing a dragon to brumate. Both of mine will just slow down and then come spring, they are full of energy and attitude.