Better ingredients, better technique, better results

For the bird:

20-22 pound turkey, cut into parts, back bone removed
2 sticks unsalted butter
3-4 Tbs kosher salt
2-3 Tbs ground black pepper
6 Tbs finely chopped fresh sage

Melt the butter in a small saucepan, then add the remaining ingredients.
Using a pastry brush, brush each of the turkey parts and place in a large pan you don't intend to roast in.
Cover with plastic wrap and refridgerate for about 22 hours
About 2 hours prior to roasting, take the turkey out of the refridgerator, unwrap the plastic and place in the roasting pan you plan to use. Try to space the parts for more even cooking and browning. Two pans might be necessary, just rotate the pans halfway through the cooking process. If you have a convection oven, even better, and you can also put the dark meat in one pan and the breast in another pan, taking one pan out when the tempurature is correct.
Preheat the oven to 450, and when at tempurature, put the turkey parts in the oven and roast for 15 minutes on high. If you have two pans, roast them separately.
Turn the oven down to 325 and return both pans to the oven.
I roast the breast until about 180. Most recipes call for 160, but we just like our bird done. The brining helps the meat from drying out. For the legs, about 170. With the meat separated into white and dark, you can cook each to perfection.
Rest, lightly covered with foil, for at least 15 minutes. Your resting time will also be shorter than normal because your parts are smaller.

Turkey Stock

Have your butcher cut up your bird, keeping the neck and the backbone for stock. I usually get my bird two days before, allowing me to roast the neck, backbone and even the wings in the oven, the day I bring the bird home, so I can make my stock that day, and allow to cool overnight and skim. That gets me to Wednesday the day before, and I have stock ready to go for both the gravy and the stuffing.

Cooked parts of Turkey, leftover carcass from a previous meal, roasted back-bone, neck or wings as long as they are already cooked
1 sweet onion, cut in half, gritty root end cut off
2-3 stalks celery, gritty bottoms cut off
2-3 carrots, scrubbed, gritting tops cut off
3 whole garlic cloves, smashed
2 bay leaves

Place all of the ingredients in a large (12 quart if you have it) stock pot, cover with water, bring to a boil, and then keep on a low boil for 2 hours.
Strain out all of the solids and discard
Let the stock cool down for a couple of hours, then refridgerate overnight
Skim the fat off stock prior to using. Freeze in 1 quart containers for convience
Use this stock for both your gravy, stuffing baked separately, and your turkey soup with the leftovers you will have because you cooked an enormous bird in parts.