Well... persistence pays off.
I called Virgin on Saturday morning on the off-chance that they had found a spare seat and - hurrah! - they had.
So, 20000 Flying Club points later I was happily upgraded into Upper Class.
The difference it made to the journey is hard to overstate. The flight was still long, tiring, boring, sticky, smelly and horrid but it was on the acceptable side of tolerable: I was able to sleep, I didn't have to queue for hours anywhere, I could relax in the lounge before departure, there was space to move in the cabin. It made all the difference. It made giving up my Sunday and disrupting my life slightly less painful.
Hurrah for Virgin - the new Upper Class Suite really is very, very good. I was a little disappointed by the service from the cabin crew (they were understaffed, however and they did explain this at the start) and I got the distinct impression that there was a hierarchy of passengers - which I was at the bottom of - but they were minor quibbles. It was much better than BA's club world and just reinforced my belief that Virgin are the best airline around.
One tip, though: 12K is worse than Seat Guru tells you. Not only do you have the beauty area in your face, you're in a corner where the cabin crew can't see you. I was almost missed out on at least two occasions.
So... I intend to make the most of my time out here. There are several colleagues I want to meet. The product I'm working on is going to be very big and I want to make sure I'm at the forefront of our efforts to make it a success. Being based in a different country and different timezone to the majority of the team means I need to shout twice as loud :-)
I'm not looking forward to my return trip later in August. It's a discounted economy ticket with no possibility of upgrade :-( Given that I'll be missing the UK's summer Bank Holiday in order to fly, I'm particularly upset by that. It's my own fault for booking so far in advance... I won't make that mistake again ;-)