Just a note on domestic departure gates, they can be any of A1-A9 and A11 (where A4 is a bus gate) all at or towards the north end of T5A, and A19, A22, and A23 all along the south end of T5A. It used to be the case that A19, A22, and A23 were not domestic departure gates so you could go to GC North knowing you would only have a short walk to your gate, but that has changed and you could easily get one of the gates at the other end of T5A now.