Actually if the OP has the flexibility to pick a day when the YYZ-MXP operates, and if MXP is OK for him, YEG-YYZ-MXP is the only one stop option.
If preferring to fly to Linate, then YEG-YYC-FRA-LIN might be best.
Not sure why people seem concerned wth FRA. Sure, MUC might be somewhat better bt I find FRA to be easy to navigate. Use the tunnel.