Originally Posted by
szerfam
At end of May flying to LHR leaving on Tues-Wed return can be Friday or Sat. Although it is business it is on my own dime. I could leave from MSP, BOS or JFK. Just wondering from what city i would have best chance for an op up on a discount economy fare. The M fares are more than double the H fare so would like to try to avoid that. Any other thoughts on this, other than buy J or M and SWU if I want to sit in the big boy seat would be appreciated!!

Op-ups to LHR are not very common because it is a business heavy market. In fact, during the winter months you can often see a near full business cabin but wide-open coach cabin.
That said I would probably try MSP for an op-up. Seems like higher loads than JFK and certainly higher loads than BOS.