[QUOTE=SK AAR;34975924however, it may be that you will be offered to checkin your bag to Toronto for free if the flight is full or the aircraft type (CRJ) has limited overhead luggage capacity.[/QUOTE]

On the CRJs you just leave the large carry-on at the door and they will be put in the belly of the plane. You can then collect them at the door of the plane again when deboarding.