The trip from Switzerland to Germany with the train was excellent and totally smooth. I stopped for 2 hours in Basel, ostensibly to get my hair cut in Lörrach. There were no passport or customs checks of questions (might have been different if I hadn't cut my hair!). The trains, as well as all shops, in Germany have a Maskenpflicht, which means you have to wear a mask. It wasn't as bad as I thought it was going to be, and people in shops, cafes and restaurants were welcoming and slightly apologetic about the mask thing. The train was totally fine, not too full and it ran on time. It was a Swiss SBB train that took me up to Mainz, so no WiFi was available.

Near Mainz I visited a winegrower in the Ingelheim area and ordered several cartons of wine for the summer. Spent in the night in Mainz at the ibis Mainz City, which was ok but nothing more (but perfectly friendly) and had an excellent meal in a brewery (Eisgrub) and then spent the evening in a wine bar (at a table in the street so I didn't have to wear a mask). The mask had to be worn anywhere in or around the hotel, as well as in the interesting Antike Schifffahrt museum over the road (which was free). Otherwise it was really great how Germany has adapted to the situation and somehow kept life normal. In each establishment you have to give your name, address and phone number for eventual contact tracing. That was done in a pleasant, uncomplicated and efficient manner. It did not apply to shops (I was in and out of REWE City and Penny for provisions), but as usual masks must be worn.