Alice
Small world. I live in Concord too. My husband and I visited the Alsace region last year but stayed in Strasbourg. We used
Orphorus Tours (Ophorus.com) but it left from Strasbourg. The day long tour took us to Colmar, Equisheim, Riquewihr, Haut Koenigbourg Castle with a stop at a winery in Ribeauville. It was wonderful. Only eight people and a great guide.
They also have tours that visit more wineries but frankly one riesling pretty much tastes like another after awhile. I enjoyed having time in the villages personally.
I know this probably won't work since you will already be in Colmar but maybe they can pick you up there.
Anyway enjoy your time. I also encourage you to get to Strasbourg. It really is a lovely city.
Jennifer from Concord too.