Most appointments will come in Feb/March, but there are some college re-apps that hear earlier.
My DS was a college re-app, and he received his appointment in January, before the semester drop deadline. He decided to stay at his college for the spring semester and looking back he says it was the best thing for him. There are a few things to consider:
-What classes are you taking in the spring, and how many of them will enable you to validate classes at USNA? think Calc 2, Calc 3, Chem, Physics etc, that will make your life much easier at USNA if you can avoid taking them again. If you aren't taking classes that will help you at USNA, there is less value in doing it.
-Are you in NROTC now? if so, and if you are not on scholarship, there is no requirement to continue it for the spring, and many people think there is no additional value to gained by repeating your 4C year. Others really enjoy it, and continue it just for the experience. Obviously, if you're on scholarship, you probably aren't considering dropping the semester for financial reasons.
-There is a lot to be said for enjoying the experience of being a 'regular college student' for one last semester. If you are successful in getting an appointment, you will have a very different experience and lifestyle for the next decade or more. The experience of living away from home, meeting new friends and learning to navigate the world on your own is something that will help you out a great deal at USNA. If you find yourself with an appointment and stay in school, you will have the freedom to do whatever you find interesting, try new activities, join new clubs, whatever, without the pressure of performance. Plus, being a college student is lot of fun, assuming you stay out of trouble and stay in shape for USNA.
Bottom line, it's an interesting question to ponder, but chances are any offer of appointment will come much later, and there are more important things to worry about right now. For college re-apps, your college transcript is the single most important factor in your application. Re-taking the SAT/ACT is also a good idea unless you scored above 1500 last time. Lots of good info on re-apps on this forum you can search.
Best of luck