I used 2 live in Boardman Twp. near Youngstown, OH, 50 miles from PIT. When I wanted 2 go only to Toronto, I would just drive !
However, U want to go during Lake Effect Snow Season. No fun being snowed in between Erie & Buffalo !
Please also note that taxi fare one-way from YYZ to Downtown Toronto is C$50 or U can take an express bus for C$13 or so pp.
Finally, award tickets are subject to a heap of Canadian & US taxes.

If U still fly, AC offers tickets from PIT @15K to anywhere in Ontario or Québec even allowing a stopover in YYZ in one direction. Is there another Canadian city which U would like to visit: Ottawa, Montréal, Québec City, Sudbury, Sault Ste. Marie, Thunder Bay...? Please note that all these are much colder & snowier than Pittsburgh (think Minneapolis.) In Ottawa in January U can ice skate on the Rideau Canal past the lovely Parliament & other downtown buildings under supervision of the city Park Dept.!