Southern Germany Itinerary Help

1.) That should work generally. I would not recommend outings from a Munich base to N'stein or to G-P. These outings take too much travel time. Suggest G-P as one base with a day trip from there to N'stein (a train + bus connection takes you via Reutte from G-P to Füssen... that said, I'd drop N'stein in favor of Mittenwald (train only, 20 minutes) or perhaps use the bus system to visit Schloss Linderhof instead.) Just stay in Munich for your time there.

Map of trains/bus lines to Linderhof, Mittenwald, Eibsee from G-P:
https://www.dbregio-shop.de/uploads/files/RTWerdenfels_Streckenkarte.pdf

2.) Boppard should work quite well for your Rhine/Mosel base. Free transport from there with the VRM Guest Ticket (which you get from your innkeeper) to all your destinations (except Bingen/Bacharach.) There's not much in Bingen; I'd recommend Marksburg Castle in Braubach instead, or Rüdesheim, depending on your interests.

You have a lot of great places listed. Very nice. I'll just add a few thoughts:

1. Rothenburg ODT - There are mixed opinions on this forum. I personally love the place. Will be staying there again this fall. It is much better to stay overnight there, and experience it without the great masses of tour bus visitors there during the day. Visit the Criminal History Museum, and definitely take the Night Watchman Tour. If you like Christmas things, visit the Kathi Wolfahrt Christmas Store.

2. Rhine - great choice. We personally like St. Goar, it has a very nice castle to visit. Bacharach is also nice. If you have a German rail pass you can visit all the towns by taking boats (included). That is a wonderful way to see the sights, castles, etc... on the Rhine. We've spent a few nights in St. Goar and taken the ferries up and down river. Rudesheim is very touristy, but still nice. Nice beer garden halfway up the hill. You can walk up the hill to take the cable car (very scenic) up the hill, and then walk down toward Assmanhausan.

If you have more time than you’ve listed, add it to Salzburg. We’ve been to all the places you plan to go except Nuremberg. The Romantic Road was a disappointment after spending a week in the beauty around Salzburg.

Boppard is a great base for your plans along the Rhine and Mosel. We’ve stayed there before, but last year we chose Bacharach. And regretted it. A lovely town for a visit if an hour or two, but Boppard was much nicer for a home base.

If you haven’t booked your hotel in Munich, do so immediately and expect very high prices. We liked Hotel Metropol near the train station.

Hi! I just wanted to make sure that you have heard of the Deutschland (or "D") ticket which could potentially save you quite a bit on train fare. It covers all regional trains and local transportation throughout Germany for a calendar month for 49 euros. It will not work on high speed trains, but it will work all the way to Salzburg.

If you would like to know more, just let me know and I can share directions on how to sign up for it.

Couple more comments...

The DB Site: https://int.bahn.de/en
You will have some bus connections to make for the journey to Eltz and back and elsewhere, perhaps, but the DB site will provide those connections... no need to hunt down bus schedules separately

Nuremberg: I failed to comment on the 2 night-stay. Won't you need at least 3 nights for two separate day trips from Nuremberg?

Rothenburg: I see no issue with visiting on a day trip from Nuremberg, at least not in October, when crowds have dwindled some, especially if you can do it on a weekday. As for seeing Rothenburg at night... you can expect sunset at about 6 pm in October, and there are trains leaving at 8 pm and as late as 10 pm that will get you back to Nuremberg. It would not be my choice to check out that morning and tote my bags to Rothenburg for another check-in, then another check-out the next morning, and then to have to return to Nuremberg for sightseeing there or a day trip to Regensburg... Sleeping in Rothenburg for me would just be sleeping, not sightseeing, and would only put me behind schedule-wise. Rothenburg is a small town that doesn't take long to see. You will probably have time that day to do a little something in Nuremberg before you leave. Trains from Nuremberg arrive there at 11:51, 12:51, and 13:51, etc.. If you're staying for the evening in Rothenburg until 20:00 or later, arriving even at 13:51 leaves you with a lot of time on your hands in this place.

German Rail Pass: This might be worth a look for some or all of your journeys, especially if there's a fall sale in effect, . But it does not provide free river cruising on the Rhine; it will give you a 20% cruise discount, but that same discount has always been available with any train ticket used to reach the town you board in. GRP flyer:

https://assets.static-bahn.de/dam/jcr:c0b25c61-bd5a-41ac-aea9-a56b909a88b5/German_Rail_Pass_2024.pdf

St Goar: I've stayed here on separate occasions as well as in Boppard. This much smaller town might also make for a good travel base. The ferry crossing there is very convenient for using the trains on the opposite riverbank for visiting Rüdesheim and/or Braubach (Marksburg Castle.) Also, there are a few nice hotels with excellent views overlooking the Rhine scenery there. Boppard has waterfront hotels too...

Are you going to Oktoberfest for the beer or for the festival? I ask because there is also a great beer festival in Stuttgart the starts and then ends a week later than Oktoberfest. And there are two unique beer towns evening-tripable from Nurenberg. They are Bamberg for smoked beer and Forcheim for celler (keller) beer.

For the Rhine and Mosel I'd base out of Koblenz. Much more to do, especially in the evenings, and it's easy to travel either river from there.

You're not going to have time to visit Nuremberg and take two day trips.

Munich hotels are already sold out for Oktoberfest if you don't already have a room. It's actually hard to find a good place as far away as Garmisch.

Berchtesgaden shuts down in OCT. You may want to check your dates.

Coming and going from Koblenz might be convenient for certain train outings but not all. When it is convenient, it's that way only under the condition that you book in that minimally-interesting part of town near the main station (Koblenz Hbf,) which lies somewhat far from the small, more desirable old-town zone near the Deutsches Eck (where most people would prefer to stay or hang out in the evening.)

If you book in this more atmospheric area of Koblenz near the Deutsches Eck, your destinations to the southern half of the Rhine Gorge (St. Goar, Bacharach, Bingen K-D cruise dock) not only require a longer train ride from Koblenz Hbf, but you will also need to add a preliminary bus ride through this mostly modern and traffic-heavy city to reach the Hbf beforehand. This results in a total travel time of 90 minutes in order to reach Bingen Rhein Stadt (for the Rhine cruise.) Compare that with the train-only ride from Boppard to Bingen Rhein Stadt (8:15 - 8:52, 37 minutes) for the 9:15 cruise, or 10:15 - 10:58 (35 minutes) for the 11:15 cruise. (Double these transportation times for a round-trip; clearly, you will be adding substantial travel time from old-town Koblenz.)

If you check the DB schedule, you'll find that traveling up the Mosel to Cochem from the Deutsches Eck in Koblenz is no faster than from Boppard. Just over one hour in each case, and all of it by train in the case of Boppard.

Koblenz isn't on your list of destinations, but if you wish to spend an evening there, that's pretty easy from Boppard. And it's easier to make that bus connection into Koblenz's old town one time rather every time you wish to take an outing outside of Koblenz.

Hub and spoke method of travel is fine. That is what I usually do

Boppard is fine but I prefer the smaller Bacharach. You might look at places to stay in Bacharach, St. Goar, and Boppard and see if there is one that stands out to you.