Provided you booked the J/F premium fare deal from PEN, you have a fully flexible ticket... . THE CATCH is that you must fly the first segment before date/time changes are made.
If it were me, I'd probably use points, or find a decent price on the last segment SFO-YVR.. Then move the last segment out as far as 364 days from your pek-hkg segment. Then you have a J ticket, with last seat availability, at your disposal, if you want to fly last minute, on a holiday, etc.
Last edited by expert7700; Apr 26, 2016 at 11:19 pm
Reason: edited to shorten, since I see OP already was reviewing options in the premium fare deal thread.