I am afraid that recent experience of trying to get any help at all out of seating control offline is very poor. I was recently returning from Australia in F with my wife and 5 year old and we were spread about the cabin on the SIN-LHR sector and no one could do anything to help. Once we were in the lounge I didn't even bother asking again, but about an hour before the flight I was called to the counter to be handed new BPs in 5a/e/f. They must have moved three First pax to get us in those!

So my advice would be to try calling up, but don't expect too much, but make sure you make yourself known in the lounge and politely explain your predicament and hand them your BPs and hope for the best. Probably best to get there nice and early too...

Good luck!