Well, I booked the flight and just need to figure out the rest! I'll be flying into Munich on Dec 7 and out of Dusseldorf on Dec 25 (it was cheaper to fly on Christmas day). Main interests are of course the Christmas markets and then daytime sightseeing that includes churches, cemeteries, local art and whatever quirky thing I can find from atlas obscura to check out. This is the itinerary that I currently have if anyone would like to give me some feedback. Should I do more days in one city vs another?
7 Munich
8 Munich
9 Munich
10 Munich
*Possible day trips to Ulm and Dechau from Munich
11 Salzburg
12 Salzburg
13 Salzburg
14 Nuremberg
15 Nuremberg
16 Nuremberg
17 Stuttgart
18 Stuttgart
19 Stuttgart
*Possible day trip to Colmar or Esslingen from Stuttgart
20 Frankfurt
21 Frankfurt
22 Cologne
23 Cologne
24 Cologne
25 fly home from Dusseldorf