Has anyone had any luck upgrading at the airport? Have a two segment flight booked using NH miles and the first segment is in economy. Due to T-96 hours rule, I can no longer see award tickets for my departure day, but yesterday I still saw 7 open seats in J. Given that I am already paying for J in miles for my first segment, wondering if there’s a slim chance where I could upgrade at the airport. Somehow, the BKK>TYO segment is really difficult to land using miles. Thanks!