I am looking to do a nice vineyard tour and champagne tasting starting in reims but just a day trip. Any suggestions of high quality tours?
The Cote des Blancs, it is a nice 50 minute drive from Reims. I especially like Vertus : http://www.champagneescapes.com/cote-des-blancs.shtml
If you have less time you can also go to Verzenay (about 20 minutes from Reims)
There are two nice cellars to visit in Reims Pommery, which is famous and "posh" (you have to call to book a tour in advance) and Taittinger, which is in a very old cellar (call to know when the visit is in English) about 7 years ago