Preheat oven to 350°. Cut each squash lengthwise in half; remove and discard seeds. Using a sharp knife, cut a thin slice from bottom of each half to allow them to lie flat. Place in a shallow roasting pan, hollow side down; add 1/4 in. of hot water. Bake, uncovered, 30 minutes.
Meanwhile, place onion in a large microwave-safe bowl; microwave, covered, on high for 1-2 minutes or until tender. Stir in turkey, stuffing, cranberry sauce and wine.
Carefully remove squash from roasting pan; drain water. Return squash to pan, hollow side up; sprinkle with salt. Spoon turkey mixture into squash cavities. Bake, uncovered, 25-30 minutes longer or until heated through and squash is easily pierced with a fork.