Well, like you said,, at least you got a few this year, and I am sure you'll do what you can to winterize it but,,,If you go by the lies spread by the zone group, it is zone 5. I don't know anywhere in this state that is an actual zone 5. I have an email from Arbor Day where they admit it is not zone 5 but a very cold zone 4. When I buy based on zones, the ones that survive the winter here are the zone 2 and 3 ones. This past winter the temperature hit -40°F. The ground here normally thaws by mid March. This year it didn't start to thaw until mid April.
I had a couple of Reliance peaches make it through 3 winters. The last spring they had a few blooms and produced 2 peaches. I had forgotten how juicy tree ripened peaches were. I had also forgotten how fuzzy peaches used to be. The newer varieties are being produced for minimal fuzz. The following winter killed both trees.
The low temperature isn't the killer. The real killer is the January thaw followed by sub zero temps followed by the February thaw followed by sub zero temperatures.
its all a " boy I hope it makes it"