I am also in the same boat. Just booked a 3 night award stay at the Hilton London Bankside for this summer, but we will be traveling with our 8 year old daughter. Could only book a King Guestroom with points that sleeps 2. Now I know that all three of us can easily fit on a king size bed. But I don't want to run into any issues when I show up, so I've sent an email to the hotel asking about a paid upgrade to a room that will accommodate all three of us. I am Gold but I don't mind paying extra to get the into the right room for the 3 of us. Besides even if they were to upgrade me for free, I don't think the upgrade would be sufficient enough to accommodate 3 according to their occupancy rules. Let's see what they say.