I am planning a trip with my 79 year old mother beginning Nov 22. Looks like the Munich Marienplatz market opens Nov 27 this year - and that's the day we leave. Are there other markets in the city that could open earlier? I can't seem to find 2018 dates on the medieval market. I'm told that there are 20+ markets in Munich. Any help/advice would be appreciated, as it is one of my mother's bucket list items to see these markets. Thanks!
No, that is the general time frame. Last week of November, roughly a month prior to Christmas.
The Tollwood Winterfestival opens 23 November to 23 December (market) at the Theresienwiese Munich (same place as the Oktoberfest). It is closed on Sunday 25 November. https://www.tollwood.de/en/tollwood-winterfestival/
If you're up for a day trip to Salzburg, its main Christmas market opens Nov 22.