First booked two premium economy seats in the summer for October. As we reached T-14 started monitoring last min openings. 1 upgraded to J 4 days before departure, 2nd one upgraded to J 1 day before departure. That was SFO-TYO. There was even an F award seat available but I passed on it, couldn't justify 30k points for a wider seat and caviar when J will suffice.

For return leg, same thing. Two seats in J became available TYO-YVR 2 days before departure. Originally had TYO-SFO so had to make some adjustments for our repositioning flights, but of course worth it being able to cross Pacific lie flat.

Both times I called Alaska and the representatives were super helpful with changing the flights!

Tips: Last minute openings do occur, but be ready. Be ready to adjust repositioning flights. If you are traveling with someone else, have the conversation and decide in the case of only one opening who gets the seat first. Because by the time that seat shows up you may only have minutes to snag it before someone else does.