I also, would avoid smoking the turkey with bread stuffing. You could loosely stuff the cavity with onions, citrus, apples, herbs etc.; for additional flavoring.
You won't get the 270°F, after you place the turkey in the cabinet, but 225°F would be good. If you get it higher than that; the better.
If you cook the turkey horizontally, there will be a lot of juices that will collect inside the cavity, you can use those juices for the dressing you can make in the oven, after the turkey is finished. As for the juices in the cavity, be very careful when you move the turkey out of the smoker, it is easy to spill those juices on the floor, or worse on your foot. Have a rimmed cookie sheet nearby. Transfer the rack with the turkey on it to the cookie sheet, then carry it indoors.