There's no way of knowing for sure. It will depend on how crowded/busy the restaurant is, what time you arrive at the restaurant, how many in your party, whether the hosts/hostesses at the podium are allowing walk ins.
In the meantime you can keep checking online daily to see if something opens up. With the credit card guarantee requirement already in place for character restaurants people will cancel when their plans change. You can also subscribe to the February cancellation thread: http://www.disboards.com/showthread.php?t=3178762