i think what OP is looking to do is avoid the miles/money buy-in, when magically at T-24 the "miles" part of that requirement often drops off via the TOD/HOD avenue.

with J9 and P9, the flight is likely to be pretty open up front. if Y were sold out or oversold, they'd probably tighten up J sales a little bit (especially in the P bucket) to save some seats for op-ups, and one probably wouldn't see R open.

i agree that using the miles/money option into open R is the best bet right now for the OP since it guarantees the upgrade, but i understand OPs sentiment and feel there is a reasonable chance of a $500-1000 BF upgrade offer at OLCI. if s/he uses miles/money now into the open R, OP might also be offered a $$ HOD to GF. last two times i upgraded W fares with GPUs, i received <$800 buyup offers into GF at OLCI.