If Vrabel is the only option, then wait until next year. He can't win with a much better team he ain't winning here and he's a headcase who pisses off his players and also has been fighting for full control of a team which is why he didn't get a job last year.
If you have a shot at getting a real solid guy like Ben Johnson then do it. Interview him behind Mayo's back, I don't give a ****, Mayo should be put on notice anyways.
But if they really can only get a Vrabel type, pass, show the league you will give the next coach at least some time, try to get some more talent so we are a more attractive landing zone, and then clean house.