Dan
I live just north of Des Moines, about an hour from Grinnell. I am very active in the local car culture. I am unaware of a cobra-specific club in the area, but there is an awesome Mustang club based in Des Moines which has members who own all types of hi performance Fords, Cobras included. The club hosts cruises, autocrosses, an open track event, the largest Ford show in the state, and dozens of other events every year. Here's a link to their web site:
Mustang Club of Central Iowa
Sam's right - the cold and snow does shut things down a bit over the winter. So we redouble our efforts to enjoy the 8-9 months of nice weather. I actually enjoy putting my cars away for the winter. I can do maintenance, upgrades, etc., while they are tucked away. And when spring arrives, it's like the first time all over again as I fire them up and go for that first ride of the year.
Give me a holler when you get to Grinnell.
Doug