We are an American family that has lived overseas for several years, and our kids (6 and 3) have never really experienced a "traditional" Christmas in a place with snow, Christmas trees, etc. We're intrigued by the idea of a mid-December trip to Germany. We can get a pretty direct flight to Frankfurt from where we live and are thinking of taking a train from there soon after arriving and heading south/east. I tend to try to stop in too many places when I travel in an attempt to maximize the trip, but we've learned with kids that it's better to prioritize and avoid moving around too much. I think we would spend a few days in Munich as one base and maybe a few days in another city and then do day trips from each. I spent a week in Bavaria in summer once and loved it, but doing it in winter with kids will be different.
Main things we want to see/do are: Christmas markets, medieval towns, castles, and snow. I recall loving Dinkelsbuhl, Oberammergau, and Salzburg when I went before but am not sure how they are in winter. Have heard good things about Nurmburg and Rothenburg ob der Tauber especially at Christmas, but I know they will be crowded.
Any suggestions on itinerary are most welcome. Our kids are experienced and good travelers, but obviously we don't want to jam pack a schedule for them. I'd be particularly interested in whether people recommend renting a car or taking trains at this time of year and with little kids.