I spoke with Aeroplan and i was told that the first flight the day before his 2nd birthday I would be fine. The flight from ORD/YUL (On his birthday) I would need to buy a full fare.

I was also told that even though the first leg being the day before if the flight was delayed and such by 1 day I would then be required to pay full fare from the first leg.

Its a bummer as I was able to build a perfect itinerary and the "fees" were to be only $800 for three of us. Now my other possible routes/dates the cheapest is $2700