A couple of months ago I booked Business Class Award Travel with One World (AA miles) for September. I had no problems except that we fly from JFK to LHR on Saturday arriving London at 6:20 AM and I could not get any flight on BA to Venice until late Monday night. Since booking it, they have changed that flight to even later, meaning we are not only "stuck" in London for two full days but we won't arrive at our Venice hotel till after midnight. No way to start a relaxing vacation. I have been calling once or twice a week without success for a different flight on Sunday (hopefully from LHR, but LGW is OK too). We are also perfectly willing to do that short leg in economy rather than business, but no seats available. We'd be willing to just buy cheap tickets for that segment ourselves, but of course that would cancel the whole itinerary!

Any suggestions? How likely are they to add more seats for award travel between now and then? And when am I most likely to get those seats?