Spend 4 days in Paris or train to a smaller more quaint location

If you've been there before go somewhere else like Lyon.

Well, I am so not a city gal but I love Paris. It DID take me a while to love it....mostly because I did a Rick Steves Best of Paris tour and learned how to get around and manage because I wanted to see what I was missing! I can't stay away now.

IF you do choose Paris (which would be the easiest), I'd avoid the big museums like the Louvre, the Orsay and the Orangerie. All 3 are extremely crowded. IF you want any museums, I'd consider The Cluny Museum of the Middle Ages (the cool tapestries of the Lady and the Unicorn are here), The Army Museum (if you have an interest or if any of the teens are guys) or the Carnavalet which is free so if it felt too crowded you could easily leave. One of your group might have a special interest and there might be a museum for it.

I usually stay in the 7th which many on the forum don't care for as they feel it's too staid. That suits me to a "T", lol. If I am having a quiet day I'll get lunch at a local boulangerie and go sit in one of the pocket parks at the edge of the Invalides/Army Museum complex and enjoy the outdoors or take myself to the Tuileries or Luxembourg Gardens which are huge BUT I don't need to entertain teens!

Have they watched Midnight in Paris? It's by Woody Allen and stars Owen Wilson, neither of which I like but I love this film. The steps for the time-traveling taxi are at Saint-Etienne-du-Mont.

Cafes, window shopping, history and eating abound.

A street location in Paris well known to Rick Steves' readers is Rue Cler: https://www.ricksteves.com/watch-read-listen/video/rue-cler.

Many of us have stayed on Rue Cler, including me for an entire week in 2012, loving every second of it. However, there are other locations with a "village Paris" vibe, too. Here's a Rick blog about finding village charm along Paris's market streets: https://www.ricksteves.com/watch-read-listen/read/articles/paris-a-city-of-cozy-neighborhoods. Consult Rick's travel guide and Lonely Planet for reliable hotel suggestions.

The time of year made my week-long trip unforgettable: January. During the winter months, Paris probably has a quarter of the visitors it has during the summer and shoulder seasons. Like countless Americans over the last century, I felt like I had the city to my own. However, you might be visiting the Paris during the summer or shoulder seasons. Even then, Paris is a jewel because of its world-class culture. I've also visited Paris in September and October, and it was great even with many more people compared with the winter months. There's no better place for cafes, window shopping, historical sites and eating.

The pros are limitless number of great sites: Louvre, Orsay, catacombs, Pere Lachaise, Musée de l'Armée, Jewish neighborhood, Left Bank sites, the famed Avenue Champs-Elysees, Eifel Tower, Sacré-Cœur, Sainte-Chappelle, Luxembourg Gardens, Musee Rodin, others.

Cons: A hotel on a noisy street.

You can consider Brussels Belgium to stay for 3 days. It's a wonderful city with great architecture. The train ride between Paris and Brussels is 1 hour and 25 minutes

Paris - for all the reasons mentioned above.
I love Lyon, but it is far to go back and forth for only three days.
If you decide to stay in Paris, the Hotel Bedford offers connecting rooms.
https://hotel-bedford.com/2/language/en/
We've stayed here twice since they have very large connecting rooms.
When we stayed in July 2024 we had them set up one of the rooms with twin beds. Everyone was happy.

For me, the best thing about Paris is just walking around, seeing the parks and gardens. I don't go in for the museums at all. It is a big, crowded city, but it felt very manageable to me on foot.
I don't know if you have made your flight arrangements back from Corsica yet, but here is the Man in Seat 61's information about train travel between Paris and other cities. Just scroll through to see them in no particular order. I was going to suggest Amsterdam, but it's 3hr20mins, so too long for you.
https://www.seat61.com/international-trains/trains-from-Paris.htm
Be sure to pay attention to which station you're coming and going from, especially if you are arriving at night and transferring out to an airport hotel.

Paris, Paris, Paris.....There are some crowded areas, but it isn't Times Square on New Year's Eve. There are dozens of alternate sights to see and love besides the crowded Louvre, Orsay, etc. Walking around the Eiffel Tower is a unique experience, and it is close to the Army Museum (Napoleon's Tomb), the Rodin Museum, the beautiful Pont Alexandre III, the Grand Palais and Petit Palais. Those are just things within walking distance of each other, and away from the crowded Louvre. There are many, many beautiful churches as well, all over the city, some of which have concerts. St. Denis holds the tombs of many French kings and queens. A ride on a vedette from the Pont Neuf is a one hour, relaxing view of Paris sights, and very cheap. Do remember that when the Olympics were televised last summer, the crowds were enhanced by the games. Yes, the city is busy and has lots of tourists, but I wouldn't stay away for that reason. There are so many places and things to see.....don't shortchange yourself. Paris is in a class by itself.

By the way, if you go to Belgium, pick Ghent or Bruges over Brussels.

I'd stay in Paris, but try to do things that are not on every tourists list.

Take the teens to the National Air and Space Museum. It's just 6 km fro the city center, and they have a fantastic collection. You can get there by train (I have) but it's a 10 minute walk from where the train lets you off. The last day I was there there were several school groups touring, but almost no one else. The kids seemed to be having a very good time. There are flight simulators for a lot of the old aircraft that got a lot of attention. The café is good too. https://www.museeairespace.fr/en/

Take a 48 minute train ride to Reims. Tour a champagne house, visit the cathedral where Joan of Arc crowned the King of France, visit a very interesting car museum.

Rent a car for a day and drive to Verdun. Let the kids climb around the old forts. or visit one of the many American monuments. https://www.abmc.gov/

Visit Marché aux puces de la Porte de Vanves or Marché aux Puces de St-Ouen and get your souvenirs at the flea market.

"our family likes people watching while lounging at cafes, window shopping, touring local historical sites, and eating."
Paris, just don't go to any of the places with lines to get in.

Use the Officielle des spectacles to find places not filled with visitors https://www.offi.fr/
Here are two suggestions: Arts et Metiers museum with the early modern inventions, airplanes, cars, early science laboratories on display. Fascinating. Gustave Moreau museum: I sent my teen one summer knowing that he'd like these sort of tripie symbolist paintings.
Or go to the Musee de Montmartre or Musee de la Vie Romantique and sit in their gardens. There will be a little line to get into the Rodin Museum, but it's worth it and the garden is wonderful. There is plenty to do without fighting crowds.

Thank you for all the input - seems like we should definitely consider staying in Paris for the 4 days.

Good move! 4 days in Paris is just not long enough. It takes that long to get your feet wet.