I have booked CDG SFO in Premium economy and have a buy up offer CDG to SFO segment for $1700. I have requested an upgrade with pp and there are 11 open seats on map and at least 9 for sale. Not sure what to do. I also need to do the extra spend to make 1k again...and not sure I'll have another opportunity. Any thoughts on how likely this offer may stay in my account? Or if i should hold out for the upgrade and find a way to spend the money on another flight?