A friend just checked rates for the Lyndhurst, NJ area. Every Marriott within a 50 mile radius is charging $500-1000/night, depending on the distance and how "fancy" it is, and all of them are prepaid rates.
Except one, and there's a pretty big "catch".
Approx 40 miles SW of the Meadowlands in Princeton NJ (roughly halfway between Philly/Trenton and NYC), the Residence Inn Princeton-South Brunswick hotel (4225 US Highway 1 P.O. Box 8388 · Princeton, NJ 08543 USA) has rooms for $119 that do NOT require prepayment. Unfortunately for most, the rate is only valid for federal employees and active duty military.
SO... if you're a federal employee or are serving in the military, you can book as many as TWO rooms for the $119 rate. It can be cancelled as late as 4pm on Friday 1/31/14 without penalty. If you're not, but know someone who is and who woudln't mind a free weeked in New Jersey, get them to book the room for you and TAKE THEM WITH YOU. The flexibility of cancelling plus the room being only 1/4 the cost of other rooms means you're still ahead cash-wise.
Here's the link to the property:
I would STRONGLY recommend defensively booking a room now.