If you confront a sellout situation at a hotel you would like to stay at you have one more option. Ask if an "out of service" room is available. That's industry jargon and it means you're willing to accept a room that has been temporarily taken out of general inventory due to a small flaw that needs repair. This small repair can vary from fresh paint to redoing the bathroom tile so make sure to ask the specifics to see if this is something you are willing to live with.