This is actually the perfect example of when to use Priceline. Learn how to bid using free rebid zones to let you rebid multiple times per session at betterbidding.com. A couple of years ago, a friend was often getting London hotels at the pound rate, but in dollars (like a £150 room would cost him $150 instead).
Also ask at your workplace (or by your profile, perhaps your parents' workplace), if their corporate travel agent could get you a room. The arrangement we have with ours is that they'll make personal hotel reservations for free, since they receive a commission, and we get the corporate discount for personal travel (helps to maintain the volume for the discount). I tested it out once, and they returned a price for a Marriott in London a good £20 less per night than the absolutely lowest rate I could find anywhere online, including the last minute sites and Kayak.
(I'd gather a good agent could swing a sweet deal at the Crowne Plaza-The City over New Year's. That area shouldn't be seeing a single business traveler of any means, but rooms still have to be rented.)
International Homo of Mystery