I am leaving home at 4am. 7 is not an option if u want to b curb side for the parade. Lol
USDA says that size will be done in 5 hours or so at 325F. Here is a recipe for slow roasted. Calculate for your size
Here is a site that says it is unsafe to slow roast. I'm not sure I agree with that, if it is unstuffed. I don't think bacteria can grow and thrive at 200F. Stuffed, yes unsafe.
Ironically USDA says you can cook turkey at 325 from frozen and that takes about 50% longer.