This late in your zone I'd wait until spring unless you can move a large rootball intact. We know spring will work. Now probably would also but there might be some risk.

I'm really not sure if there is any difference. I move lots of trees, including pears, until the ground freezes as far down as a Z5. I've always felt the danger lies in frost heaving which can be avoided with a thick mulch. Heaving is said to sometimes leave roots exposed, killing them in colder climates.

Pears are the worst trees to transplant I grow and the only species I don't like moving bare root when more than an inch in diameter.

Mulberries are the only species I grow that seem to suffer here from fall transplanting, where I often get considerable die-back, but trees survive.

Fruitnuts advice is reasonable, I see no advantage to moving the tree now.

thx for advice, guys.