Step 1: Thaw the turkey if frozen. Remove the neck and giblets (liver, gizzard, heart) and set aside for another use. (Be sure to empty both the front and main cavities.) Rinse the turkey with cold running water inside and out. Fold the wing tips under the body.
Step 2: Make the brine: Pin the bay leaves to the onion quarters with cloves. Place the salt and maple syrup in a very large stockpot or other large food-safe container, like a Cambro. Add the hot water and whisk until the salt is dissolved. Whisk in the cold water, whiskey, and peppercorns. Let the brine cool completely. Add the turkey, leg end up, and the onion quarters. Jiggle the turkey as needed so the brine flows into the cavity and the whole bird is submerged. Cover with plastic wrap and brine the turkey in the refrigerator for 24 hours. Invert the turkey half way through so it brines evenly.
Step 3: The next day, light your smoker according to the manufacturer’s instructions and preheat to 250 degrees. Add the wood as specified by the manufacturer.
Step 4: Smoke the turkey until the skin is browned and the internal temperature in the thigh reaches 145 degrees. This will take 4 to 5 hours. After 3 hours, start basting the turkey all over with melted butter and baste again every hour.
Step 5: Increase the heat in your smoker to 400 degrees, if possible. (Some smokers don’t go that high.)
Step 6: Otherwise, set up a grill for indirect grilling and preheat to medium-high (400 degrees). Transfer the turkey to the grill (over the drip pan).
Step 7: Baste the bird with melted butter and continue roasting until the skin is browned and crisp and the internal temperature in the thigh reaches 165 degrees, 45 minutes to an hour. Baste once or twice with the butter.
Step 8: Transfer the turkey to a platter and drape a sheet of foil over it. (Don’t bunch the foil around the bird or the steam will make the skin soggy.) Let rest for 20 minutes, then carve.