Unfortunately GI does not still make Mild Winter, at least to my knowledge. I used to love that beer and haven't found a good replacement.
Workingman Mild from Revolution is really good. It’s not packaged though. Check out the tap list at the brewpub.
I had a solid one from Smylie Brothers in Evanston like a year ago but that doesn't seem to be on tap anymore...
Good question ... Spiteful has a great one, but its draft only (in spite of my suggestion that they can it ). If you find a good one on the shelves let me know.
I'm working really hard to make this happen again. Tweet at Goose and tell them I need to get in there and make a batch.
For anyone interested, Half Acre has White Noise on at both taprooms and available for growler/howler fills at the shop.