Side trip from London

Jeffrey, you are WAY, WAY too ambitious. In a nutshell, such a day trip from London is not do-able. If you mean setting up shop in the Cotswolds, you could do some of the villages for a half day and either Warwick or Stratford for the other half of the day, but even then you'd be marching from place to place without much time to enjoy them. My suggestion is to take the train from London to Bath and see Bath and Wells on the first day. (Love Wells!) Then the second day, I would take your group on a Mad Max tour from Bath (recommend the Stonehenge/Avebury/ Castle Combe/Lacock all day tour), then return to London.

I agree- too much to include in one day. As an alternative to the above suggesstion, you could take the train from London to Stratford-upon-Avon. Spend the morning seeing it. Then take a 1/2 day trip through part of the Cotswolds (check with the Tourist Information office as soon as you arrive). We did that once and went on a "van" tour. There were about 12 people on the tour. It gave us a tastes of the Cotswolds. You might want to contact the Stratford TI ahead of time.

These are great suggestions. I read about seeing all these sites on a large bus tour for a day and thought I could be more efficient using a private van and tour guide. Do you know of any guides who do this trip?

I cant imagine any tour company trying to combine Cambridge (which is East ) with Stratford and Warwick which are Northwest. Dont recall ever seeing one. As said above Stratford and Warwick are a very full day rom London. You need nother day for Cotswolds, and another half day (at least) from London to Cambridge.
Also on a saturday you will find many Brits travelling to these 4 sites, so the roads will be busy and parking a chore

Agree with everyone else. Can't imagine a legitimate tour operator offering a one-day trip to all those places. Frankly, it would be difficult to simply drive from London to all those places in one day.Cotswolds deserve at least a couple days of exploration, on foot and in a car. The rest are half days to two days, I think, depending on interest. Except the castle.

Agree with everyone above. Impossible for a day trip. You would need three days for the above. Cambridge for one day, the Cotswolds for one day and you could combine Stratford-upon-Avon and Warwick Castle (on the same train line).
The Cotswolds are small narrow roads, some tour companies do a half day here combined with somewhere else but just half a day in the Cotswolds you would see hardly anything.

I recommend Alan Price at Celtic Horizons for a group the size of yours - he charges by the hour, no matter how many people in the vehicle, and his service and knowledge of the area is supreme. You get a personalized tour. He doesn't do Cambridge (too far north) but does do Oxford. Contact him by email and ask for his recommendation with the itinerary you have in mind.

He doesn't do Cambridge (too far north) but does do Oxford. That's a good excuse ... Cambridge is exactly 5 miles further from Charing Cross - the official point of measurement in London - than Oxford. Doesn't want to, more likely. If he doesn't want to, fair play and more power to him. Don't blame it on how far it is from the equator though.

We have always used Gray Line tours for our day trips. We have used them inside and outside of London (Cotswolds, Windsor Castle, Bath, Stonehenge), Paris, Rome, Bruges, Canada, Boston, New York, Australia. They have you meet the tour at Victoria Station or they pick you up near your hotel. You can book the tours while in the U.S. on-line. Elaine