Hi
You can check in your luggage dtd. I would try and get there as early as possible, apparently lines start early. You cant check your luggage in at the hotel unless its with certain airlines. It maybe you will need to book a taxi getting it on the normal wdw transportation would be nightmare.
At least once the luggage has gone you can go off somewhere for a while and enjoy your last day. We were going to do this last year, but decided to wait at the hotel as they take your luggage from the room and keep hold of them for you.