if you upgrade the connection on the return, you’ll be able to do a same-day-confirmed (SDC) change at 24 hours before your ORIGINALLY BOOKED departure time to any connecting flights with available F seats … if there’s a wide-body on JFK/ATL-SEA with four open F seats, that might be worth looking into (note however that SDC costs $75 for anyone who isn’t Platinum (Gold?) Medallion or higher status)