Mary Stella, as far as I'm concerned, I live in one of those cold areas.
I know, all you folks up north will laugh at me for saying this, but gosh, it is just cold down here. Cold and damp!
Like you, I would love to have some input from those who plant garlic in the northern tier of states. When do you plant, when do your harvest. I plant all mine mid to late October, and will harvest the hardneck in mid to late May and the softneck and Creole a couple of weeks later.