Southern Germany in November - itinerary advice?

Is there a specific reason for Baden-Baden? It impacts suggested routing.

There are many great options along the main/fast route to Aachen, more than you have time for. With the best connections, you'll need to spend about 5.5 hours on the train and in stations - not bad at all. To include Baden-Baden, a different routing and an additional 2-2.5 hours of train time and additional changes of train will be needed.

Because travel time/cost vs. boots-on-the-ground time may be a concern - especially in November, when daylight is in short supply - and because Rick Steves tends to make Baden-Baden sound more significant than it is, I would encourage you to look closely at the alternatives before choosing Baden-Baden and the routing you'll need for it (a routing that will exclude certain other very worthwhile places.)

We don't know about your personal interests, so specific recommendations might be premature. I suggest you look into the places on the more direct route. Personally, I'm enormously fond of Nuremberg, a city with great feel, an outstanding old town zone, and a lot of variety, a bit like Sarah Lee (nobody doesn't like it ;) The other cities can be good too, depending on what interests you of course. (Baden-Baden to me seemed a good bit less engaging - but then casinos and spas aren't my thing.)

Munich > Nuremberg > Würzburg > Aschaffenburg > Frankfurt > Cologne > Aachen

If instead you choose to include Baden-Baden and do the longer train journey, your routing out of Munich is different, but the same from Frankfurt onward:

Munich > Augsburg > Ulm > Baden-Baden > Frankfurt > Cologne > Aachen

Some further information:

Baden-Baden is where my ancestors come from. I'm traveling with a neice and would like to visit our roots. I realize it's not optimum, but it is fairly important, as it is unlikely that we will have the opportunity to return. I would also like to include Trier, if possible, only because I've been told it's beautiful.

I could add another day if necessary but of course don't want to spend all our time on trains. I will have about 5 days in Aachen and can backtrack to the east if necessary to cities such as Cologne (been there), Bonn or other suggestions. Once in Aachen I hope to take in more towns to the west, including Bruges.

After So. Germany I will have more than a month in Paris, so I could take a few days and take a targeted return trip to several towns I will otherwise have to miss.

Any thoughts are appreciated. Thanks for taking the time to contribute.

How about Munich>Baden-Baden>Heidelberg>Middle Rhein valley (St.Goar, Bacharach, or other town)>Aachen. But 4-days doesnt leave much time in any of those places. Heidelberg is the most cuttable of those.

OK then, it's the Baden-Baden route and a stay there or thereabouts. Strasbourg FR could be an outing from there if you can spare a day for it. Or perhaps you stay in Strasbourg FR if as Ashley says B-B makes for a weak place to stay in November. Strasbourg seems popular with just about everyone. From there you could visit Baden-Baden for a day, either as a day trip from Strasbourg or on the way north from Strasbourg to Heidelberg or to some other destination (the station at Baden-Baden has luggage lockers.) This last option would be sleeker.

Here's how it would look for an on-the-go itinerary that includes Baden-Baden and Trier. 2 different options for Days 1-2. Do option B if Baden-Baden is important and merits extra time.

Option A
Day 1: Munich > Strasbourg by direct TGV train, 4 hrs. Drop bags, see the town.
Day 2: Strasbourg > Baden-Baden (spend most of the day.) PM train to Heidelberg (1.5 - 2 hours total train time this day.)

Option B
Day 1: Munich > Baden-Baden (about 4 hours.) Half day in B-B.
Day 2: Most of day in Baden-Baden. PM train to Heidelberg (about 1 hr.)

Day 3: In Heidelberg. PM train to Trier (about 3 hours.)
Day 4: In Trier. PM train to Aachen (about 4 hours.)

IMHO Trier is worthwhile but only if you are into Roman history. It's nice, but not exceptionally beautiful, if it's beauty you seek. And it adds a LOT of detour time. You might consider Mainz for Night 3 and Day 4 - a university city that doesn't take you astray, great old town zone for pedestrians, handsome Romanesque cathedral and a few other treats.

https://www.tripadvisor.com/Attractions-g187393-Activities-Mainz_Rhineland_Palatinate.html
https://www.orangesmile.com/common/img_city_maps/mainz-map-2.jpg (streets in pink are for pedestrians)

Heidelberg is a pleasant place for a day. Not as impressive as Nuremberg but still worth your time.

Thank you for all the replies and the perspective. I'm not afraid of cold, rain or dark, but the waste of time in order just to get to Baden - Baden doesn't make sense. I'll probably reroute and fly from Vienna to Cologne, move on to Aachen and concentrate on spending quality time in cities in that region. I'll just have to return to S. Germany another time.

In April I fly out of Zurich to return to the US. That might be a better time for a side trip to Baden - Baden; I will have more time then.