Smoking a big bird, need advice.

I am going smoke a 23 lb turkey for Thanksgiving. I have read a lot about the issues of smoking a big bird (danger zone) but it's what was purchased for me to cook so I'd like to make it work. I am going to brine the bird and I plan on spatchcocking the bird to help speed up cook time. I have a traegar pellet smoker and I plan to set it at 300. How long should I expect it to take? Any critiques of my plan are welcome!