FlyerTalk Evangelist
Join Date: Aug 2011
Location: Barcelona, London, on a plane
Programs: BA Silver, TK E+, AA PP, Hyatt Globalist, Marriott LT Plat, Hilton Diamond
Posts: 13,051
London hotels are not typically very big, nor are they typically very strict with maximum occupancy, especially if you've already booked a large family room.
Have you considered booking 2 inter-connected rooms?