(Good-bye) until then.and (Good-bye) till then.; (Good-bye) till later.; (Good-bye) until later.
Good-bye until sometime in the future. Sally: See you tomorrow. Good-bye until then. Sue: Sure thing. See you. Mary: See you later. Bob: Until later. The announcer always ended by saying, "Be with us again next week at this time. Good-bye until then."
See also: until