Potatoes are happy on my bare garage floor until late January. After January they have to be moved up 1-2 feet, onto the cement stairs, to avoid freezing. Same with onions. Apples are better in the garage on the workbench, which is a couple feet off the ground and a few degrees warmer (but still cold). Pumpkins are happy in the basement or in a dark closet, off the floor so they avoid moisture. Carrots and parsnips are fine to leave in the ground, covered with a pile of dead leaves or a thick layer of straw if I want any hope of digging them during the winter. Otherwise they can be dug in spring, after the winter cold has made them sweeter.The link below is a 5-page handout from the University of Wisconsin which lists types of foods, their ideal storing temperature and any necessary humidity, expected length of storage, and plans for creating your own root cellar.
What will you store this year?