We had a party of 11 last December and I had no problem getting a table on my first try. Although it's not exactly a busy time of the year. However, I was prepared to ditch the boys and one of the Mom's in order to get a table. So when I called, I had my numbers ready so as not to dawdle. If they declined the reservation of 11, then I was quickly prepared to say, well then how about 7? It can literally come down to a couple of seconds as to whether or not you get the ressie at all. This way, if you can't get the table for 13, get if for the lowest number, then try again tommorow.
By the way, we all sat together at about 4 tables pushed together right in the middle of the dining room. It was perfect, we could see everything from there. Good luck!