"Also re LHR does anyone know if 2 hours is enough to transfer to Term 1 BD flts and how late in the day does the AC arrivals lounge stays open till??"

2 hours is lots of time--there are other threads on this. I prefer to exit through customs and not do transfer airside. Others think differently. I think the lineups are longer airside but that is just my experience--and I have a UK passport so getting through customs is a breeze. Fast track can be slower than UK lines.

Arrivals lounge used to be open until about 12:30-1 PM but others may have more recent experience.