Join Date: Oct 2006
Location: London, UK
Programs: BA Gold, VS Silver, SQ Silver, IHG Plat Amb, Hilton Gold, Marriott Plat, Accor Silver, Radisson Prem
Posts: 16,873
You won't be able to use the lounges in a terminal that you aren't departing from.
Head to T5 and set up camp at Gordon Ramsay, at a table overlooking the apron.