I still would let them know but if you have reserved with points, I have been assured by Member Services that they cannot give your room away even if you do not show up at all. We will be flying in from the West Coast on the red eye with an 8am arrival. I went ahead and reserved the night before we arrive to assure that a room will be waiting for us. Members Service (two different times) was adamant that the room is committed to my points whether I am there are or not, even if I call and say I am not coming. It doesn't make sense to me that a room would be allowed to go vacant but that is what I was told. It is your room for your reserved stay and they cannot give it to someone else.