"Thank you all for the information! Day tripping to Munich instead of staying there sounds like a good plan."
A good plan if in fact you want to be doing things and going places in Munich, when it's at its busiest - during Oktoberfest.
Munich represents only a tiny speck of the Bavarian experience. With options like Nuremberg, Bamberg, Regensburg, Bayreuth and Würzburg, Bavaria is overstuffed with fine places to visit, so overstuffed with museums, historical sites, palaces, breweries, etc. that one needn't set foot in Munich at all. See locations of these places on this map:
https://www.familysearch.org/en/wiki/img_auth.php/b/b7/WV-Bavaria_regions.svg.png
If you are landing at MUC airport (40 minutes away from central Munich) and don't wish to travel far the first day, the lovely town of Landshut (see map,) which is on the train route to Regensburg, is just as close to the terminal as Munich itself (35 minutes by direct train to Landshut.) Or stay on the train for Regensburg (90 minutes.)
Regensburg, with UNESCO WH status for its medieval town center, is one of those Bavarian destinations which Rick does not cover AFAIK:
https://tallgirlbigworld.com/things-to-do-regensburg-germany/
I have found the rest of Bavaria to be less crowded than durring the
summer high season. For example, I was in Stuttgart for their
Volksfest.
Stuttgart has lots to see as well as the Volksfest. But it is located in Baden-Württemberg, a hefty distance from Munich and from Bavaria.