I've never known the CCR to be closed for this flight. But if it is I would bypass the Galleries Lounge and go to BA First lounge and have full English from the Buffet bar. If you're going glorious F then you shouldn't be going to the Galleries when you can get better bubbles in First Class Lounge. Enjoy - I'm still waiting for a trip in new First. It always seems to be the next plane or the previous

If this is your first time in the CCR ask the front desk to give you the tour and services available including the Elemis Services. Also ensure you know about the CCR arrivals lounge landside at T5 for shower and breakfast. Open for a very short time in the morning.