It's certainly possible, though whether it's realistic is really up to you - what works best for you as far as pace and learning style, how much "book knowledge" you have coming in, and how comfortable you are taking tests. I took my exam about a month after I started studying in earnest, but I'm very comfortable taking those sorts of exams and am generally a pretty quick study. I also didn't have any particular deadline for getting certified - I had the luxury of scheduling the exam as early or as late as I felt ready to take it.I know there are plenty of people who would tell you that they needed several months of highly structured study and review before they were comfortable, and that signing up for an exam date that close wouldn't have been wise for them.
So short version is that you're the best person to be able to make that determination. Just keep in mind that given the timelines you don't have a lot of margin for error. If you don't pass the first time around, or get started studying for the current version but later feel you need to reschedule to give yourself more time, you may end up having to schedule your exam for after the cutover, which means un-learning the older content. So unless you're under a time crunch to get certified (e.g. wanting to have it before your current project wraps up and you hit the job market) or you're very confident that you can ramp up quickly and pass on your first attempt, it may make sense to just plan to take it in the first few months of 2016 and and prepare using the new materials, if only to minimize your risk and stress levels.