I stayed there last November on a seven-day stay with points. As a platinum, I was told that there weren't any available rooms. However, if I wanted to pay 35 pounds (or something similar), I could upgrade to a river view.
Having just gotten off of a long flight and not having my wits about me, I failed to ask them how they could upgrade me for a fee if there were "no rooms available." Since the hotel was already on points, I didn't hesitate to pay for the upgrade.