I do not see how you can show up for a reservation booked two nights before you actually arrive.
Not sure how you intend to check in. If you don't check in on the first day you'll certainly lose the reservation. The previous poster's correct, you'll go down as a no-show. Then, when you do arrive, you won't have accommodations. They're not going to hold the room for two days for you.
I also don't see how you can have someone else check in for you, as they ask for ID from the primary guest. If you know someone who can check in, you'd have to make them the primary guest and put them on the full reservation - if you did that, you'd also need a room for six, which you can't get at POR, AND you'd need to pay the nightly fee for the third adult.
Not only that but I don't see how free dining can make up for paying for two nights of rack rate resort that you didn't even use.