I did a 12lb butterflied turkey last Saturday. It just barely fit on my 18" WSM with legs tied. I find this method allows for a more uniform cook. Thighs were done when the breast was done. I suggest cracking the leg bone pre-cook to help with the dark meat cook. I just learned this tip from another thread here a few weeks ago. Either way, if you have the time, present it how you want it.