It also depends on whether or not you are a Capt or FO. For example, TPA is the most senior Capt base, but FLL is the most senior FO base (from what I've gathered at least). Its all fair game right now for FOs considering everything being changed down in FL, up north should all stay the same. If I were to guess, for FOs its about a 60% chance of going up north, and 40% chance filling vacancies down south for a month then eventually getting based in down there. Hope this helps.