you're brisket will hold in a cooler for a good many hours. just be sure to vent before putting in or it can overcook itself.
stop worrying about temp.
cut off the point, put it in a pan, cover with foil and just let it cook for a couple hours. pull it out, put on the grate for a bit to bark up and you're good to go.
-In memory of a friend.
avatar by grillman. patent pending.