If you were eligible, or going with someone who is, you'd probably already know this, but... The "Armed Forces Salute" -40% off room-only is available until December 23rd.
I agree with the PP on joining AAA to get a discount if nothing else is available. Your one night POR reservation will be a separate res. called a "room-only" reservation. When you book it, just remind them to put in your reservation that it is a "continuing reservation," meaning that you'll be staying on with a package and therefore would like to remain in the same room, (just make sure you've booked the same room view category). It's not guaranteed, but usually isn't a problem. The next morning you can pick-up your new KTTW cards with your tickets/DP on them.