I see that the castle is only open Sat/Sun in Dec, weather permitting. Is there a good chance of it being closed? Would like to find out the odds before making it a major part of our trip. Thanks
See their website:
http://www.st-goar.de/733-1-test.html
It is as Lee mentioned on another thread.
The Rhein is more likely to be rainy than very cold in December.
In neither of your threads have you mentioned Christmas Markets. I would say that they would be a treat for your kids, something to do after dark. The sun sets at about 4:30 in Germany in December.
Regards, Gary
I've been to Germany once in Dec/Jan. It snowed on Dec. 26, the day we arrived, and there was snow on the ground the entire 2 weeks we were there. If you go to the area around the Middle Rhein, I would plan alternatives for Rheinfels. I see that the Marksburg (www.marksburg.de) does have winter hours. It's a complete castle, with a lot to see indoors. Rheinfels is a ruin. Most of what there is there is now outdoors.
I have been to all the places you mention, and I never needed a car. I was sure glad I was not driving that December. One of the places we went was the Schwarzwaldbahn, a rail line which traverses the very scenic Gutach river valley between Offenburg and Donaueshingen in the Black Forest. The river valley was particularly spectacular with the fresh new-fallen snow.
Rheinfels has a good museum but Marksburg is indeed worth a stop no matter the season; it's the only one open for tours on a regular basis year-round in the Rhine area.
I'd suggest staying in Koblenz or in Mainz in winter - smaller Rhine towns like St. Goar are just TOO quiet, and there are many more indoor options in the larger towns.