Can anyone with experience of this route offer a little advice?

My wife and I want to fly to LHR-JFK_LHR in CW for a weekend. We are pretty flexible but will probably travel in may or june, leaving on the thursday and returning on monday.

It will be my wifes first time in club and ideally we'd like to be in the upper deck yet neither of us have status or full J tickets so will have to wait for tythe lottery of OLCI.

My question is....are there certain flights or certain days that are less busy with business travelers or those who can bag all the upper deck seats?

Thanks