Day trips from Paris in Oct/Nov

For day trips there are 2 books you can look at. "Daytrips France" by Steinbicker which focuses mostly on trips from Paris, with directions for either train or car. Another is "An Hour from Paris" by Simms which focuses mostly on travel by train.

Versailles or Fontainbleu for chateau visit.
Chartres, Rouen or St Denis for cathedral visit.
Giverny for Monet's garden.
Provins or Senlis for country town feel.

http://www.planetware.com/paris/paris-day-trips-f-p-psur.htm

Decide where you want to go then research transport options.

There are literally dozens of day trips you can do from Paris within an hour or so by train. Some obvious choices, Rouen, Reims and the Champagne houses, Tours and van trips to visit the chateaux, Auvers sur Oise where Van Gogh lived his final days and of course Versailles, Chartres, Fontainebleau, Giverny (it closes end of October). There are also tons of lesser known and charming spots like Senlis, Moret sur Loing, Crecy la Chapelle, Conflans Ste. Honorine etc etc You can see snapshots of some of our trips here:
https://janettravels.wordpress.com/category/day-trips-from-paris/
You don't need a guided tour for any of this. If you wanted an overnight you could also go to Strasbourg for a night easily from Paris, but I'd stick to things closer in. Paris itself has plenty to keep you occupied for this length of time.

If you bicycle and would like a personally designed day trip to some out of the way little towns around Paris www.frenchmystiquetours.com organizes bike trips -- he has facilities for selecting bikes, plans transport and guides the trip. If you enjoy bicycling this is the best way to enjoy the region. There are also local bike trips called 'Fat tire bike tours' to Versailles, Giverny and around Paris.

You might also take a look at Ina Caro's Paris to the Past, which describes a lot of day trips from Paris by train, including many of those listed above. I agree with Janet, no need for a guided tour.

There are lots you can do by train on your own:

Versailles is very easy and quick to get to from Paris by RER - rent a bike if you want to extensively tour the gardens.

Vaux-le-Vicomte is open daily until November 2nd and you can catch a train from Paris and be picked up by a shuttle bus that takes you the rest of the way. After November 2nd it is open on weekends only.

We recently did Giverny/Monet's Gardens and Rouen by train in the same day (spent morning at the gardens and the afternoon/early evening in Rouen).

Also did Reims on our own as a day trip by train. There are a number of champagne houses/cellars in the center of Reims and you can easily walk to some (ex. Mumm's) or get a taxi to the others a little further away from the train station. If you want to get out to the vineyards outside of the city, you'd need a tour bus or a car rental - although I can't say there would probably be much to look at in the vineyards out that way in late October/early November.

We also did Normandy as a day trip from Paris. It is a very long day, but still worthwhile if you don't have the time to stay overnight. We hired a private guide for a 9 hour tour of the American sectors and he picked us up at the train station in Carentan and dropped us off at the end of the day in Bayeux. Some guides also do half day tours if you only want to focus on a few key sites. Not sure if, or how often, the group tour buses go out in the late Fall, but most of them seem to run out of Bayeux if you don't want to hire a private guide/driver.

Thanks everyone for your suggestions! We have some research to do!

A few coments:

Giverny is a good day trip but the gardens may be rather bare in late October.

My adult son and I visited Normandy in late October a couple of years ago; it was chilly and windy so make sure you have a good coat. It was a great 2-day trip - we took the early morning train to Bayeux, had a wonderful lunch at La Rapier, and spent that afternoon walking around town and visiting the tapestry. The second morning we met up with Olivier in the city parking lot behind our hotel; he's a tour guide for Overlord Tours and he grew up in and knows the history of the area. He gave us and a family of 3 a wonderful day-long small-van tour of the battlefields/towns/cemeteries and then delivered us back to the train station to catch the 6pm train back to Paris. Highly recommend!

We only did Versailles as a day trip and it was worth seeing, just to see the sheer magnitude and opulence). We also arrived about 8:40 and got in pretty quickly and tended to walk faster than others, so we were actually in the Hall of Mirrors with only two other people (vs. the hordes I've seen in others' pictures).