Hand out exam tasks on December 20th and give time until January 7th.
Plan is to have them as tasks, a bit similar to homeworks. There are certainly parts that can be achieved more easily and some that may take a bit more thinking to achieve. As the baseline passsing would require 50% points from exam. Challenge is always to come up with something that hopefully does not have readily available solutions on the Internet and where you actually learn yourself something useful and thus build confidence on what you can now achieve after this course. Clearly, the partial solutions are also solutions, just receiving a bit fewer points.