Since you're already booked, it may not matter. But you didn't say where the "up north" was. I found that many hotels up north in business cities have lots of availability over holiday periods as business travel is very low. This means point stretcher dates too (hope you checked those). But more than that you can frequently find very cheap rates at those hotels at those times, and earn more points to use at times when rates are higher. It can be worthwhile playing around and seeing if paying might actually net you more than burning points.