I'd prefer to dig the potatoes when the temps are colder in the fall to store them. Is it OK to leave them in ground a few months if the tops are dead?
As long as you don't have field mice or voles,You should be ok.
And as long as you aren't getting too much rain.
Last year I accidentally left a few potatoes in the ground all winter long. They sprouted during the following April. When I dug them up, they looked great. They were in much better shape than the main crop that I dug up in September.
We have plenty of winter rain, but the ground doesn't freeze. And our soil is sandy, well draining, and can be dug reasonably even when wet. I think these factors favor leaving the potatoes in the ground. Your mileage may vary.
This year, I'm leaving them in the ground and only digging up what I'm ready to eat.
i have covered potatoes, beets and carrots with straw and left them in the ground over winter. the carrots turn oh so sweet when left in the grown. and the potatoes are crunchy (i like raw potatoes but they need to be ripe) and sweet left in the ground.
a root cellar can do the same thing if you put about a bed of about a foot of sand and add a little water now and them to keep the humidity up.
it all depends on how hard your winters are.
Zero days for me. I had broccoli and Brussels sprouts seedlings to put in the potato patch.
I think you'll just have to experiment because a lot depends on your weather and soil conditions. In my garden they would be riddled with slug holes if I left them in the ground through a soggy British winter.
In zone 6/7, you probably will have deep freezing.
So, beside other reasons, you have to dig them up before they freez. You can dig a bigger deeper ditch in the garden and store them in there.
Becase potato has starch,lots of it, its composition will change and will get watery soft; not edible.
I live in North Central WV, just south of Morgantown. I've always just dug mine as I've needed them. Sometimes digging significant snow off the ground first. Been doing this for 5 years. No problems.