Pre Planning for Winter 2021/ Spring 2022

That is a lot of questions. Just note that winter is not really off season in Switzerland and Austria, unless you stay away from the Alps.

A good day trip from Prague can be Brno, even better is to spend a night there on the way to Vienna. Between Vienna and Switzerland it can also be a good idea to stop somewhere inbetween. Liechtenstein is an option, but there are more interesting places in my opinion. Not sure what you mean by "the scenic train" in Switzerland though.

From Switzerland to Nice the best option depends on where in Switzerland you start. A direct flight can save a bit of time, but depending on where you start the train can be the faster option. In any case, the train will give you better views. It is a scenic ride, both through the Alps and along the Mediterranean.

Since you are trying to cover quite a bit of territory, you might want to look into the OBB Nightjet trains. Spend the night sleeping on the train and wake up at your destination the next morning. I believe that they may serve some of your destinations. See YouTube blogger Paul Lucas Wingin It for some good reviews. Happy planning!

For this plan, the Nightjet can be useful between Vienna and Switzerland. You can see a map of their network here: https://www.nightjet.com/de/dam/jcr:6a8041cb-0131-4ad3-84fd-25154548e5dd/nightjet-streckennetz-deutsch.pdf

Nice is an excellent base for visiting places on and near the Riviera but is impractical for a day-trip to Marseille, which is over 2-1/2 hours away by train. A day-trip to Lyon would be impossible; it's over 4-1/2 hours away. Lyon has a lot of sights. I'd recommend multiple nights there on the way from Nice to Paris.

Before committing to visiting Marseille in the off-season, I recommend Googling mistral.

Good day trips from Nice are Cap Ferrat with Villa Ephrussi and Villa Kerylos, replica of an ancient Greek home. Nice town of St- Jean there too. Also Antibes, and St. Paul de Vence as well as Vence with Matisse Chapel. Half a day is enough for Monaco.

This is a jam packed and ambitious schedule, very exciting. Since you’ve been to London many times already, have you considered nixing it from your trip? There are usually direct flights into Prague for the same price. I have been to Prague twice and it’s easily becoming one of my favorite cities. Letna Park is a must see, some of the best views of the city. There is a beer garden up there (letenský zámeček) grab a drink and stay for sunset (which sets right behind St Vitus) and you won’t regret it. There is also Vyšehrad which has a gorgeous walking path along the river. A stunning basilica and one of the oldest cemeteries in Prague. It’s a little more off the beaten path, so less of a tourist crowd (Prague can feel crowded at times). You can take a day trip to Terezín concentration camp that is about an hour outside the city. You can also take a trip to see Sedlec Ossuary which is a church decorated with bones.

I would definitely recommend the train from Prague to Vienna. It’s very affordable and is less time and hassle than flying. Schönbrunn Palace is a must see. I spent hours walking around the gardens. If you’re into music, I would look into getting tickets for a show at the opera house. A good day trip from Vienna is Bratislava. I didn’t make it over there when I was in Vienna but I had a friend stay for a night and said it was the highlight of her trip. Another stop to consider is Budapest. It is an easy train ride from Vienna and it’s a city I think often gets over looked.

I wish you the best in your planning!

If looking for Swiss cities (non-Alps), consider some or all of Zurich, Winterthur, Bern, Basel, Luzern, Geneva.

Switzerland can be expensive. Breakfast could cost you the equivalent of $30.

In France, Lyon is definitely worth a stay for even a couple of nights. Be sure to see some of the Saint Croix neighborhood, high above the old town.

Many thanks to all who replied, Brilliant responses!

Hello,
A couple of thoughts to add
My wife and I took a day trip to Lichtenstein because of my desire to add another country to my "been there" list. I have to say it was a delightful surprise. We had a wonderful day. It was easy to get there via bus and I think it was worth it. There were luggage lockers as we stopped in route to Zurich which leads to some Switzerland comments. We loved Switzerland. Zurich, Bern, Interlaken region (recommend Murren) are all musts. For a different look Geneva is also worth a visit. We also went to the Swiss National Park which is in the region where the locals speak Romansh (among the other languages spoken). If you have never been to Switzerland, I would put it way ahead of Prague and Vienna. if you like to hike, then not even close, Switzerland is a much better place to visit. Next on our list of favorite areas in Europe is the south of France. Like Lichtenstein, we were surprised at how much we loved the area. We used Juan les Pins as our base due to free stay at the Marriott. With a rail pass we went up and down the coast and ate in Nice every night (about 30 mins from Juan Les Pins). The trains were convenient and frequent. Nice was wonderful and food was excellent. Monaco was worth a day trip. Antibes, Cannes are also great places. to visit If you are in to some old Roman history, you can go further northwest from Monaco. It was about a hour or two from Juan les Pins so it was too much to do on our last trip. I would make Antibes (sand beach, Picasso museum) my base next time but you have to plan way ahead due to limited places to stay. Juan les Pins was ok due to free stay but not much else for our family of four.
I was in Prague when the temperature was over 100. It was hot and crowded with tourists. It was worth the visit but I wont be back. I will go back to Switzerland and the South of France which is always the best indicator for me on how much I enjoyed the place. We would also return to Monaco. the views are stunning at the top. Hope that helps. We are going to Spain for a couple of weeks in the fall assuming Europe opens up for those who have been vaccinated. Keeping our fingers crossed. We plan to go to Madrid, Barcelona and Seville. Is Granada worth a visit? thanks

Ambitious plan, cities like Prague and Vienna deserve minimum of 3 days.

Switzerland is awesome, but expensive. Interlakken is a great place to stay and base for day trips, In Winter, if you drive in Austria and Switzerland, you might need chains for your tires, with a good snow storm. Lucerne is a great city to visit.
If you happen to be near Lichtenstein, stop and visit for a short time, but don't make a significant detour to go there.
The French Rivieria and Provence are great places to visit, you could spend two weeks, just in those areas. Monaco, Cannes, St. Paul de Vence (wonderful village on top of a hill all made of stone). Skip Marseille.
Going up the Rhone, there are many places to visit, Avignon, Arles, an intact Roman Aqueduct named Pont du Gard https://prd-wret.s3-us-west-2.amazonaws.com/assets/palladium/production/s3fs-public/styles/full_width/public/thumbnails/image/wss-aqueduct-roman-france_0.jpg

Viene is a stop as well. Once you get to Lyon, take the bullet train to Paris.

I was on the Riviera for a week in mid-March. After researching the mistral, I decided to concentrate on the westernmost area. Since I had to fly into Marseille I did spend 2.5 days there at the beginning and enjoyed it very much. On my second full day, the mistral came. Though the day was sunny, I did my best to keep out of the strong cold wind and had a good time. Then I based in Nice for 5 nights and used the local train to Antibes, Villefranche (my favorite), and Menton. All were interesting to explore (the RS guide was very helpful), it was delightful to sit at a table on the boardwalk in the sun. St. Patrick's Day was fun - there are several Irish pubs in Nice. The Chagall museum is a must-see if you are a fan. There weren't many tourists, so no crowds or waiting for a table anywhere.

Since all your other destinations are northern, consider starting in Nice/Marseille.