Had to rep you for this. The more I think about it, it is a good idea, and more helpful than the Wizkid's local stores look up feature. There is a calendar on this site that potentially could fill the same role you are talking about. Maybe coordinate with moderator of that?
When I checked it once, there were only a couple entries on it.

I travel my fair share too, and would love to have a quick reference to find a drop in game somewhere