The real issue it to make sure it is cooked right to begin with. Cook until you get an internal temperature in the thickest part of the thigh (not touching the bone) of 170Â°F.
I have used my Weber grill with a rotisserie ring for turkeys almost every year for 7 or 8 years now and I still go back and review the Weber web site every year.
It has great guides for figuring your fuel needs and times depending on the size of your bird.
You also want to consider how you are serving it. Some people serve the bird whole and slice at the table. I slice and place on a platter. This takes longer so you need to plan for it. Either way you want everything else to be ready to go at the same time. (that is perhaps the hardest thing… especially if you are waiting on family)