OPUP on LHR NBO route in Y

Hi,
I have an upcoming flight to NBO from LHR in economy but it is a Y class (full fare economy)booking. I know that this route is always heavily over booked and even more so at this time of year.
I was wondering, in you experience what the likely hood is of getting an OPUP to PE? I know from experience if you ask about upgrades they always offer you the paid for option in LHR. I also know that if I was flying the return NBO to LHR it would not be unusual to get UPOP'ed to UC on a Y class fare at this time of the year. I know I can use miles but I would prefer to save for a redemption ticket.
FYI and Flying gold as well.
Thanks
Eddie
I have an upcoming flight to NBO from LHR in economy but it is a Y class (full fare economy)booking. I know that this route is always heavily over booked and even more so at this time of year.
I was wondering, in you experience what the likely hood is of getting an OPUP to PE? I know from experience if you ask about upgrades they always offer you the paid for option in LHR. I also know that if I was flying the return NBO to LHR it would not be unusual to get UPOP'ed to UC on a Y class fare at this time of the year. I know I can use miles but I would prefer to save for a redemption ticket.
FYI and Flying gold as well.
Thanks
Eddie