SO....early January in Germany (starting out in Frankfurt/Mainz area)....what to do/see?
Seems that we will be going there for a late family Christmas. Many thanks to Vlad Putin (because of the war and the flood of Ukrainian refugees, the boy is stuck in Germany and can't leave. He is studying in Germany, and needs a student visa, which you get in-country....but all appointments are booked for months and months by the refugee flood, so he just has to stay put and not risk not being let back in the country to finish his studies). Daughter will fly over from the UK to meet us. We are pretty sure we need to say WITHIN Germany, due to the boy's visa concerns (we just aren't sure about him traveling in the rest of the Schengen area). We'll be in Mainz at first, where he is studying.
We will spend family time together, probably get together with German family outside of Koblenz that weekend, but we'll have some time to be "touristy" for a few days. I'm sure that the first week of January is not a peak tourist season. Many sites may be closed. BUT, some won't be, there will be some other things to see and do. We haven't seen Nuremberg, Munich, or Dresden...maybe stuff there? We all love Berlin, maybe we visit there for a few days.
Bottom line, any good options to see/do in central to southern Germany the first week of January?