CU seems to give preference to those students who scored above their average. There are a couple of 21's who just managed to get an interview, and there are LOTS more trying to get it. A late interview itself won't matter. It's the quality of your overall application.
Last year, a guy from Cornell interviewed in March. He still got in everywhere.
for the last cycle, my interview was on 1/27 and I received my acceptance around mid-february. As long as you have solid stats (22+ DAT and a reasonable GPA) and a good interview, you shouldn't have any problem getting in.
My interview is in the end of Dec. but when I asked about it hurting my chances they said they had less interviews before Dec 1st this year and it shouldn't hurt at all.