That sounds like a fun game; I’ll save it.
I think my Grandmother must have done some version of a very slow-cooked turkey, because that bird was in the oven by about 6 or 7 AM, and we usually ate about 4 PM. I wish I could remember more about how she did it...
-JT
Here’s how I do the turkey (sounds like your grandmother’s method).
The night before or early in the morning preheat your oven to 400. Place thawed turkey in roaster, cover and pop it in the oven. If it’s huge, more than 15-20 lbs, make sure it goes in the night before.
Roast it at 400 for 30-40 minutes (25 minutes if it’s tiny).
Immediately turn temperature down to 200 and let it slowly roast all day (all night and day if you put in in the night before), from 10-24 hours. It will turn out perfectly-it’s the only way I’ve ever had success with turkey.