I'm just a few miles North of the Ill. border. We ususally have about 5 months of frost free growing here, give or take a few days depending on the year. Last year longer, this year shorter. My other peach tree is a Flaming Fury
PF24 C, which is supposed to be one of the most cold hearty. I just planted it last year, and I let it keep about 6 peaches on it just to try them. They aren't ripe yet, but will be in a few days. I like the fact that they are not all ripe at the same time. Reliance is also a cold hearty peach, but I tried it twice and the tree died both times. Madison is supposed to be a cold hearty peach, but my tree never made it past the first winter. Tru Gold is another one that is touted as a cold hearty tree, but only seems to be listed in Gurney's, and after trying for three years to order a tree, and always being told it's out of stock, I quit trying. Funniest thing is that just weeks after getting notified it's out of stock, they run an add with it "On Sale" on the front cover of their catalog. I'm bretty much done ordering anything from them.