Take this for what it's worth but my Mom swears to it...
She says when she was growing up (you know the walking uphill both ways to school barefooted in the snow days) that my Grandma would cook the turkey, then my Grandpa would take it out of the oven and put a layer of foil on it. Once he had the foil down tight he would put 8 or 10 layers of newspaper around it, wrap all of that in a quilt and put it in the trunk. They all piled in the car and drove 4 hrs to my Great Grandmas. She swears to this day no Thanksgiving turkey comes close to as good as those were.
So I'm thinking, preheat an ice chest with hot water, wrap in foil and layer a slug of newspaper and you should be good for hours.
"But really, is it possible to have too many grills?" My Misses...
Old Oklahoma Joe
Weber Smokey Joe
Weber Jumbo Smokey Joe
Weber Classic Premium (Jessi)
Weber Summit Charcoal (Waylon)