Thanks to everyone that chimed in, I think we have a great itinerary (at least the large parts) that we feel great about and excites us. Fri-Mon in London Mon - Wed in Cotswolds Wed-Fri in Bath
Fri - Sun back in London (fly home Sunday) I decided that we'd probably do the day trip to Dover and Canterbury from London and we may do a day trip to Wales from Bath (although, it would be a long day). We are happy that we are not spending a lot of time in the car and will capitalize on the area around London.
Sounds fun. Have a great trip!
If you just want a taste of Wales, Cardiff is a short (aobut an hour) train ride from Bath. I really enjoy it- great shopping in unique shops in the Victorian arcades and market (in an old church!!) The castle (not one of the best, but still....) is right in town. I 'd also encourage you to do at least 1/2 day out to Windsor from London. Personally I'd cut a day in the Cotswolds or one from Bath to 'do' Windsor... but to each their own.
Also works to your advantage for getting the weekend discounts that many London hotels have.
Cheers!