I have a trip planned YVR to Asia where for the AC portion I have options to go via HKG or PVG or PEK, then on to my final destination. I am mostly interested in upgrading the long leg over the Pacific (ie. YVR-???). I will try to do this with my remaining blue certificates (4 day upgade window for me).

Are all three options (YVR-HKG, YVR-PVG, YVR-PEK) equally likely to have upgrade seats or would my odds be better on one of them over the others?

I have not yet booked and am flexible on which of the three I route through. Suspect HKG may be tougher than the other two but wonder what the more experienced FT'ers say.

Any advice?