Preheat oven to 325 degrees F. Coat a large roasting pan and a 2-quart baking dish with cooking spray.
Remove the giblets and neck from the turkey and reserve for Giblet Broth. Remove any visible fat from the turkey. Rinse the turkey well and pat dry. Rub the cavity with lemon halves, squeezing them as you go. Make a few tiny slits under the wings, where the legs join the body and in the fleshiest part of the breast. Stuff each slit with a bit of rosemary and sage.
Stuff cavity and neck pouch with about 5 cups of the stuffing, securing neck cavity with a skewer. Place remaining stuffing in the prepared baking dish; cover and refrigerate until needed. Sprinkle the turkey with salt and pepper. Place bacon slices crosswise on the breast. Cover with a piece of cheesecloth big enough to drape over the whole bird. Dribble oil over the cloth to moisten slightly. Tie drumsticks together.
Place the turkey, breast-side up, in the prepared roasting pan. Roast for 1 hour. Pour wine over the turkey and baste a few times. Continue to roast for 2 hours more, basting with pan juices several times. Remove cheesecloth and bacon and roast until the turkey is done, an additional 30 to 60 minutes. (An instant-read thermometer inserted in the thickest part of the thigh should register 180 degrees F and 165 degrees F in the stuffing.) Total cooking time will be 3 1/2 to 4 hours.
While the turkey is roasting, make Giblet Broth. About 30 minutes before the turkey is ready, cover the reserved stuffing with a lid or foil and bake until heated through, 35 to 45 minutes. If you like a crisp top, uncover for the last 15 minutes of baking.
When the turkey is ready, place it on a carving board or platter. Scoop stuffing into a serving bowl, cover and keep warm. Tent the turkey with foil and keep warm. Pour drippings from the roasting pan into a small bowl; chill in the freezer so that fat can be skimmed off. Place the roasting pan over medium heat and pour in broth; bring to a boil, stirring to scrape up any browned bits. Cook for 5 minutes, then transfer to a medium saucepan. Skim fat from chilled drippings and add drippings to the saucepan; bring to a simmer. Mix water and cornstarch in a small bowl; add to the simmering sauce, whisking until lightly thickened.
Remove string from drumsticks and carve the turkey, discarding skin. Serve with stuffing and gravy.