I think there’s a guy out near where Cty N and I-94 interchange that may be close for you. I can’t remember the name of the place, but he’s got a car sign out front and he sits back off the road. You can see his buildings from the frontage road, and it’s North side of the interstate.
I buy mine at Moore’s on Mineral Point Rd also. DeForest may be the closest for you depending on your location.