Do you have status with the chain. If so, the local hotel may have to give you a room. Do you stay there often/ever? If so, while a guest visit the manager. Otherwise, get the manager's email. rather than catch him or her off guard and in a bad mood on the phone, try a nice email or letter. Explain why the weekend is special and ask if they can not put you up if he can refer you somewhere that can.

Be charming and good luck.