A week in Paris in November

Well obviously, train transportation for 4 people are going to add up, you mentioned you're keeping an eye on expenses.

Perhaps you haven't thought about how the short days will cut down on your sight seeing. If there is sunshine (and in late November that can be rare) you'll only have about 8 hours of it. There's so much to see in Paris and at this time of year the holiday lighting makes the evening hours a joy. The usually lovely French countryside will be in winter drab.

Important too, at the time of year you're planning to visit, to check websites to verify opening times.

https://www.timeanddate.com/sun/france/paris?month=11

If you are getting the Paris Museum Pass, which is typically a good idea if you'll be visiting museums, Arch de Triomphe, gargoyles on Notre Dame, Fountainbleu is included on that. It is a relatively short train ride and is less busy than Versailles and you wouldn't need to change hotels. (Versailles is on the pass, too, if that's of interest) I do also like the Chartres option, too. The hotels depending on what you are looking for, will generally be less than Paris and the cathedral in Chartres does not have an admission charge. The town is appealing, too. When I was there there was a light show on a lot of the buildings. It was fun. If I am remembering correctly, train fare to Chartres was about 10 euro

The Navigo Decouverte fits your dates perfectly, would cover airport travel if you want to do that (although a cab for 4 is only 50 or 55 each way) ; it would let you go anywhere in the Ile de France. It would not cover Chartres, Reims or Rouen, but it would cover lots of great places that are closer to Paris and all your transportation all week within Paris for only 22.50 a head plus 5 for the card. four TGV tickets to and from Reims will add up; going to places closer in would be 'free' once you had the ND pass.

One of the main attractions of Reims is the champagne. I don't know if the teens will enjoy it so much if they are under 16. Wine is legal from 16, so if you are okay with it, it might be a good choice for an overnight.. There's a cathedral, a basilica, a WWII museum too. The champagne tours are more about the history of each family and winery and can be very interesting.

I would not want to be far from the airport on Monday morning. You'll need to be at the airport 3 hours before the flight, and Monday morning traffic toward Paris can be slow. Of the 3 towns you mentioned, none has trains directly to CDG. The best connection seems to be from Reims - take the TER to Champagne-Ardenne (12 min.), then easy transfer to the TGV to CDG (32 min). It's an easy journey and trains hourly. If there's a problem with the TER, you can just take a taxi to Champagne-Ardenne. The other 2 towns require taking a train into Paris and then going from one train station to another.

So you could go to Reims and then to CDG at the end of your trip. Or you'd have to split your time in Paris to go to Chartres or Rouen. I haven't been to Rouen, but Chartres is good for a day trip - though an expensive train trip for a single day.

You could take the TGV to Strasbourg (just two hours) and visit the Christmas market, which will open Nov 24. Check to make sure lodging is available. The problem with the places you've mentioned is they'll just be so GREY .. .go somewhere that specifically counteracts that with all the lights and magic!

https://noel.strasbourg.eu/en/accueil

But I'm realizing you have far less than a week with a Tuesday arrival and Monday departure -- you'll be hard pressed to do everything you want to in Paris in that time (about a half-day with jet-lagged arrival on Tuesday, then five days - Wednesday through Sunday). I'm not sure you really need -- or have time -- to head anywhere else.

I would say to do a day trip, not overnight. You have so little time in Paris, don't waste it on logistics of moving to another hotel, train tickets, etc.

If you just want the experience of being outside the city in a smaller town with more open space, Chartres could be good -- it has an "old town" area as well as the cathedral. In the bookstore at the left as you enter the cathedral you can rent audio-guides in English.

Fontainebleau could be another good choice, though I haven't been. As an earlier comment points out, it's included in the Paris Museum Pass. Also, within the RER system, you can just head off to Parc de Sceaux.

I agree that you do NOT want to be outside Paris on Monday morning. Give yourselves plenty of time to get to the airport and go through security.

Thank you everyone! This is all useful advice and I appreciate it!

You only have 5 full days. You will definitely not run out of things to do. I suggest you stay in Paris. If you get the Paris Museum Pass (4 days - 62€, 6 days - 74€) you can go in and out of museums at your leisure. If the weather is bad, or you need a bathroom, museums can be a lifesaver. You an see what the pass covers online. Instead of buying it at a large museum like the Louvre, go to a small museum to avoid long lines.
http://en.parismuseumpass.com/

Be sure to get to the airport 3 hours before your flight.

Some of the Christmas Markets open around Paris beginning November 24. I believe the one by Sacré-Cœur - Monmontre is only opened weekends until closer to Christmas. I enjoyed St. Germain & at the end of Metro line 1 is Grande Arche- La Defense market.

Galleries Lafayette & Printemps both outside windows/ lights and inside. Views from Paris from inside Galleries Lafayette I think floor 7 get you rooftop.
My teens enjoyed the regular street markets 7 - 2pm in Paris too. They are usually around metro stops, I remember the Sunday one Richard Lenior/ Bastille & Grenelle or President Wilson on Wednesday, The sewer tour and catacombs are great for that age group. Mine enjoyed the artist specific museums; Picasso, Gali & Rodin. The area around the Sorbonne is more youthful too. There were tons of teens at the mall inside by the Louve.

So make your day trip decision after you arrive. Never know how you’ll feel once you get to Paris.
Public transportation is excellent so make sure you get the extended bus/metro pass.

Usually after 3 nights in a hotel there is a savings, and if you’re renting an apartment there is the one time cleaning fee, so it’s cheaper to home base one location vs changing places.