Sandy, let me know how your Creole does. Like all plants, some just don't do well in certain climates, but even in cold zones, there may be micro-climates that will allow many of the softnecks to grow. As the name indicates, Polish White came out of Poland and much of Poland certainly has cold winters. I lot of our softnecks originated from Asia and Eastern Europe and some of those grow fairly well in northern climates. Polish White is well-knows to do well in your zone. I have never heard of Western Rose, so I don't know where that one originated. Most of the softnecks originated from the Mediterranean region though and those varieties just won't do well in your area. Creole varieties originated from Spain, all of them as far as I know, and they simply are warm-growers. I have never heard of anyone even in zone 6 grow them successfully. But you may have the exception to the rule.
I grow a lot of garlic, hardneck, softneck, and Creole and there is a lot of differences in these garlics, not just storage. Did you know that garlic is even rated by "garlic-experts" in flavor and pungency, just like wine and cheeses are rated? Some garlics are even beautiful in color, ranging from pink, brown, red, burgundy, and of course white. To most, Creole has the most eye-appeal, surely stores the longest (how about one year or more!), has great flavor and pungency, and holds its flavor even when cooked.
I had planned on writing an article on garlic, not only about how to grow it, but its history, and the differences of each major category of garlic. I just never got around to doing it.
