NEED HELP! 18lb butterball fresh turkey

I have a large egg.
Did a fresh 17 1/2 lbr last Thanksgiving from a local farm.  I let it sit in a brine overnight, then cooked it @ 300 - 325 on a raised grid indirect as high as I could while still being able to close the lid. I think it took 2.5 hrs if I remember correctly. It was delicious. I forget what I put in the brine, because the flavor of the brine you barely get (at least in my experience). I know I put brown sugar, kosher salt, 8 -10 smashed cloves of garlic, onions, rosemary, thyme, and a quartered/squeezed lemon to get a subtle flavor.  Only a quarter a handful of pecan chips (My mother does not like a strong smoke taste.)

It was delicious. Although I had a remote thermometer, and checked with a thermapen, the meat closest to the bone needed a bit longer even though the temp read fine. If I was getting the same size bird, I would do it direct spatchcocked on a raised grid. But I do not know how you could do big of a bird on a large spatchcocked. I know others have done it, but If spatchcocked mine, I do not think it would have fit. And once you cut it.....well..... Perhaps others will comment.

This year, I ordered a 11-12 lb bird, with 2 extra full legs and 2 extra drumsticks. Gonna brine everything together Monday night to Wed early AM. Then I am going to let it sit uncovered in the fridge to - 1 Thursday. It will be spatchcocked. and cooked direct.  The legs will be on on a raised second level.
When it is done, we will eat. Family likes to eat about 2:30 - 3:00 so they have two turkey meals: one at 3 and a turkey sandwich about 8 PM.

For an 18lber, I'd go whole, indirect at 350. Figure on about 15 minutes a lb and give yourself at least 20 minutes to allow it to rest. Don't think you will be able to spacth it and have it fit. Here is one I did that was 18.5 lbs. Could barely get sausage on around it. Don't be afraid to do the whole FTC trick if you need to start early and it finishes before you are ready to eat.

Looks like you placed the beer can directly on the plate setter rather than on a grate- that would be the only way to fit a 16 pound turkey I am guessing (I usually do it on a grate and barely fit a 12 pound).  Great idea!

@robnybbq That's exactly the info I have been searching for. My wife just ordered two 16lb birds for our two Thanksgiving dinners. Now I know how it's done. THANK YOU!

Ok. Found my notes. I was off by a lot of time. I put the bird on at 9:45 am and pulled it at 2:15 pm. The bird was 17.42 lbs. apparently the breast meat down closest to the legs was not quite done and I stated that it probably needed another 30 minutes. Dome temp was 340-360, which means it was cooler at the grid. Everything else my memory was correct. At least that, makes me feel a bit better, and that I am not totally losing it....