Please don't low-n-slow poultry. It doesn't really assist in tenderness/juiciness at all with whole birds. Your brine, injection, and pulling from the cooker at the proper temperature will more than take care of that. Plus, you will have rubbery skin and the bird probably will take on too much smoke in the amount of time it will take to finish a bird that big at temps that low. I would highly recommend somewhere between 350-375 (for great crispy skin and decent cook times without sacrificing tenderness) for "probably" around 4 hours. Shoot for 165 in the thigh. To keep from drying out your breast meat which will be done before the thigh/upper drum, you can ice the breast meat (think gallon-sized ziploc icepack full of crushed ice) for 1/2 hour while you get the cooker/bird ready to go. I wouldn't wrap a bird at all, except MAYBE shielding the wing tips/drum tips for a PART of the cook as mentioned. And make sure you go easy on the smoke wood chunks, turkey is a smoke sponge! Good luck!!