It depends on the reason. I have managed to have this done at many hotels in the big four chains.. It starts with the situation you have.. I book what ever it takes to get me in.. I do make sure its cancellable.. and then call the elite line to see if I can change it to one night.. usually it takes me a couple try's to get this to work.. but it does work "most" of the time.. now I know if its a special event.. you can't do it.. but if its the run of the mill sell out.. or a convention.. again.. not a major one.. but something not that big you can work around this.. so just keep trying unless its a major event