I am flying NH from SEA to NRT the first week in Sept in Y. It's a United codeshare UA9669/NH1077. I'm a US Chairman (*Gold), currently in a window seat 33A toward the back of the plane. The plane, which according to Seatguru is the older, less comfortable seat configuration 777-200, is very full.

What are the chances of getting an upgrade to Premium Economy and what is the best strategy for doing this? I don't get to SEA until 80 minutes before the flight and then have to transfer from the A to the S gates. I'm willing to use some of my US miles to upgrade if necessary, but of course, I would prefer a gratis upgrade.


Thanks for any advice!