As the OP, I was told the u/g code to PY was N.....It was very difficult to book and in fact on my return flight YVR-YUL I had to up/g to J which only cost me 6 e/ups rather than 2 to PY as I was booked in COMFORT. This is the published schedule if you check the AC site.
However on my outbound, I inquired about J up/grade. First I was told no space, then later I was told I couldu/g to J if I would fork over more E/ups.Then, more confusion, I was also told I could not upgrade twice from Comfort to PY and then to J. Total Hogwash.
I settled into PY which was decent enough and I will earn +15% COS bonus due to Comfort booking class.
Meal was either chicken or beef and fairly decent. Wine or drinks were few, certainly not J service....but crew recognized me as a SE and I got a bit of extra attention.....Overall, happy..