I have a two reservations booked through two separate airlines for this Thursday. The first is on Air Canada YYT-YUL. The second is on United/Continental YUL-MSY. Please forgive me if the answer here is obvious. Is it possible to combine the reservations to one United ticket? I'm worried about weather delays in Canada. If I miss my flight out of YUL what will happen?

Thanks in advance.

JD