Great question BoneCrusher. This property is defined by the Govt. as being in zone five yet we mostly annually see minus twenty-five and some years minus thirty-five degrees actual temperature which are clearly zone 3 and 4 temps. Other than the hundred or so wild pear trees naturally fruiting away here I don’t have experience with any known pears fruiting here. Some of the wild pears are fire blight resistant while some are not.
I did some research though that parallels your thinking and decided to plant some pears this past spring. Went with Golden Spice, Gourmet, Patten, and Stacyville from Fedco seeds in Maine-
www.fedcoseeds.com. We had a deer camp in Stacyville and that place has very significant winters.
Also purchased Harrow crisp, Harrow sweet, Magness, Potomac, Seckel and Summercrisp from Cummins nursery in NY -
www.Cumminsnursery.com
Also purchased a number of Advent pear, Malus pear, and Rifle Pear from Blue Hill Wildlife nursery in PA.
www.BlueHillWildlifeNusery.com. They were listed as zone Five but had seen temps in the minus twenties so I took a chance.
And also went with some Keiffers also from BlueHill thinking it a long shot but maybe there might be a place on the property they could grow. Total bought pears planted in Spring 2020 was around 55. The pears from Blue Hill in PA were huge and far more grown diameter and height wise than Cummins and Fedco. Still I would order from Fedco and Cummins again as their trees were OK and mostly not found elsewhere. And it wasn’t that their trees were weak but rather that the Blue Hill trees were super large and extra, extra healthy looking.
It has been an extremely hot and dry summer here so the trees are going into fall at a somewhat weakened state; thus whatever pears if any survive this coming winter should do well here with more normal summers. Note; If rain continues to avoid us the trees will get one good watering before winter to give them a fighting chance.
Hope this helps a little.