Sorry if this is a daft question, and sorry again if I've posted in the wrong place...
The T5B Club lounge seems to get much better reviews than the T5A north and south lounges, with several posters commenting here that it's quieter and more relaxing. At the moment, my next scheduled flight out of LHR is long haul, and I'd like to try out the T5B lounge - this makes obvious sense if the flight is departing from a B- or C-gate. My experience in the past is that gate numbers aren't advertised far enough ahead of time to do much more than head straight to the gate and prepare for boarding if the flight is going from B or C. So is there any way of knowing in advance, ideally at bag drop, if the flight is due to operate from one of the satellites? It's booked for an A350 if that makes any difference.
I know that there is a way to get back from T5B to T5A on foot using the tunnel if necessary (I've used it before). I'd be quite happy to head straight for the T5B lounge then hoof it back to T5A if the gate turned out to be there, but the other half would probably think I had taken leave of my senses and I don't want to start the holiday with an argument at the airport!