Well, I'll see what they come up with. As I only need the room to get some sleep after our new year's party, I don't really care about upgrades or the like. But I'll keep you informed.

At least during my last IHG stay (CP London) I got an upgrade to my preferred room type (namely an exec room, but w/o lounge access, but they don't even have a lounge in Düsseldorf), although it was a reward stay.