I really appreciate all the posts.
We have firmed up our plans somewhat. My friend wanted to go around her birthday, so we are leaving Wednesday,January 30th, and returning Monday, February 4th. Our departing flight leaves CDG at 1:55 p.m.
I originally thought we would be going in October, and thought we would stay in Normandy, But since we are going in February, our tentative plan is to spend the first three days in Paris (I've done a long weekend in Paris in February before and it was great) and then on Sunday morning go to Mont St. Michel, spend the afternoon and night there and then head back to CDG on Monday for our flight. It looks doable, but I am a bit worried about making our flight. We are thinking about renting a car, but it looks like the buses and trains might be doable.
Any suggestions or criticisms about this plan?