Thanks to all those who provided advice. Ultimately, our dates were too tight to come up with anything that avoided or minimized YQ charges. Booked YUL-CTA (via MUN) on Luthansa and FCO-YUL direct on AC. Total for two economy class tickets: $1,274, or about $750 cheaper than purchasing tickets via AC's website.

Any tips on how to spend a 5:15 layover in Munich?