Looking at a coming of routing options, and United has an itinerary that involves a 45 min layover.
I am wondering if this is enough time. I understand that Canada flights depart as 'domestic' flights out of T3, instead of international terminal, but what about my checked baggage? Will I need to retrieve it and re-check-in?
Are you flying United/United Express metal or an Air Canada metal airplane? If it is a United operated flight then it is out of T3 and if it is an Air Canada flight it is out of the G gates in the International Terminal. You'll have to rush more if it is an Air Canada operated flight since you'll have to walk from T3 to the G gates, but you won't have to go through security again since there is a walkway between them.