Wife and I want to visit NYC fall or winter this year, we're very flexible on time, I'm PlatPro and she has no status since she doesn't fly. What are the chances of us booking any LAX-JFK flight MC and upgrading to J? There are loads of flights so is there one to target? Or are the flights too full that it rarely ever happens? Anyway to check history or you need to check daily for availability up until the T72 window?