I tell you though, if you do try to leave on Friday, 2/16, try to speak with a supervisor. When I called to update our departure date to the 16th, the girl gave me a bit of a hard time. I told her you already have us leaving from ATL to SXM on 2/16, all you need to do is switch our MKE to ATL from 2/15 to 2/16 and all will be good. With some checking, she was able to make it work. I'm not sure if leaving one day later works for you, but it may be an option.