Thanks for the post and congratulations on your soon to be new addition to your family. I think you will be having some problems in Bordeaux. 8 people is a large group and you need appointments for most visits.
You should read this article: http://www.thewinecellarinsider.com/win ... -tastings/
Are you staying in a nice hotel? If so, they should be able to help at the concierge.
There are numerous places to visit in St. Emilion, but without an appointment, it could be quite difficult.
It can be expensive to buy wine in St. Emilion. The city of Bordeaux would be less expensive for you in most cases.