Queen mated?
have you put in an inspection tray to see what the drop is before treating? There may be so little varroa drop that Apiguard not needed and you can allow queen to crack on with winter bee build up and just treat Dec.
Actually,you missed an opportunity to treat when they were queenless, as a brood gap may have allowed more varroa to be killed/ removed with icing sugar. The varroa had less hiding places.
If high drop (see bee base for an assessment info) and queen mated I would wait a couple of weeks at least as Apiguard can slow/stop her laying temporarily.