Quoting "Joachim Breitner" <nomeata@debian.org>:
is your schedule fixed already? I might try to get on the same trains, at least from Paris. Next week I might visit that international train ticket shop in Freiburg for that.
Not yet, and will take some time - so don't miss cheap connections waiting! But I will go to the Berlin train travel agency and write down the results in our wiki. Maybe you could the same.