For those who are wondering exactly how I found the fares on ITA:

OW, YYZ-SFO, advanced routing codes:
AC+ YUL AC+ yyc AC+ DEN ac+

Then select fare calendar, starting Nov 1. Plenty of midweek and sunday fares at (US) $261-$275 throughout the month. I even found YYZ-YUL-YYC-YVR/YEG-DEN-SFO (~4800 miles @ 5.4 cpm) the same way. Not great for an MR, but I'm going to SFO anyway. I just hope I can book the damn fare, and that it's not in frickin Tango

I tried variations of the above on expedia, orbitz and travelocity, no dice. All price out above $500

So calling AC direct may help? Should I even expect cooperation from them for such a convoluted routing?