Found this on Google Flights, clicked through Orbitz for booking.

Leave Mon, Nov 23 Total time: 46hr 10min
Depart
11:00 PM
Toronto, ON , Canada
Toronto Airport (YYZ) Terminal 1
Stop 1
12:15 AM
Montreal, QC , Canada
Pierre Elliott Trudeau Airport (YUL)
Airline change. Time between flights: 15hr 5min

Air Canada 430
Economy
Airbus A321
339 mi 1hr 15min
Depart
3:20 PM
Montreal, QC , Canada
Pierre Elliott Trudeau Airport (YUL)
Stop 2
6:00 PM
Beijing , China
Beijing Capital International Airport (PEK) Terminal 3
Change of planes. Time between flights: 4hr 30min

Air China 880
Economy
Boeing 777
6,491 mi 13hr 40min
Meal: Complimentary food and drinks
Depart
10:30 PM
Beijing , China
Beijing Capital International Airport (PEK) Terminal 3
Arrive
1:10 PM
Sydney, NS , Australia
Sydney Airport (SYD) Terminal 1

Air China 193
Economy
Airbus A330
5,571 mi 11hr 40min
Return Thu, Dec 3 Total time: 34hr 52min
Depart
8:40 PM
Sydney, NS , Australia
Sydney Airport (SYD) Terminal 1
Stop 1
5:30 AM
Beijing , China
Beijing Capital International Airport (PEK) Terminal 3
Change of planes. Time between flights: 7hr 30min

Air China 174
Economy
Airbus A333
5,571 mi 11hr 50min
Depart
1:00 PM
Beijing , China
Beijing Capital International Airport (PEK) Terminal 3
Stop 2
12:50 PM
Montreal, QC , Canada
Pierre Elliott Trudeau Airport (YUL)
Airline change. Time between flights: 1hr 10min

Air China 879
Economy
Boeing 777
6,491 mi 12hr 50min
Meal: Complimentary food and drinks
Depart
2:00 PM
Montreal, QC , Canada
Pierre Elliott Trudeau Airport (YUL)
Arrive
3:32 PM
Toronto, ON , Canada
Toronto Airport (YYZ) Terminal 1

Air Canada 415
Economy
Airbus A333
339 mi 1hr 32min
Arrives Fri, Dec 4 (1 day later).

Also saw lots of YYZ & YUL deals many locations: Jakarta $937, Johannesburg $956