Last year I flew IFR from KBED to CYUL Dorval and it was a breeze.

See:

http://www.langleyairport.bc.ca/html/p_04_a.htm

for some details on the CANPASS system. If you are not a CANPASS
permit holder, you will find directions on that page as well.

Coming back into the U.S. I chose to land at Burlington, VT (KBTV)
because coordinating U.S. Customs at Hanscom was too difficult and
this was my first flight to Canada, so I wanted to play everything
conservatively.

-Dave