I do not believe you can carry on your own luggage above a certain size. If it's a real issue to you, pack well & get it all in a carry on. I once went on a 2 week trip that included 3 job interviews, 1 formal night (ball gown required) & general sight seeing but managed to get everything in a garment bag.
I forgot about the last night too. You must put your bags in the hallway by a certain time the last night. You will need toiletries, clean underwear & something to wear the next day.