So I've read this whole thing as it is a description of a real road trip with a GT. One thing still nags me. Where did you put luggage? Or did you just ship it UPS ahead of you? I convinced my wife that the GT will have all the creature comforts she wants but I haven't showed her the trunk yet. We want to be able to take it to Vegas for a week. Somehow the trailer from the other topic doesn't work for me (no trailer hitch will ever find its way onto my car) and the "strap on the back of the deck lid" like you used to see in the old Corvettes and MGs doesn't work either.
You'll be amazed at what you can get in the car if you pack creatively. We use a bunch of draw-string style backpacks made of thin fabric, but don't fill them too full so we can squirrel them away behind the seats, under our legs, and of course up front. There's a lot more capacity behind the seats than you might think. As Joey said, just don't put anything up front that you don't want to get very warm. Two people and a week on the road in a GT is no problem at all, even with the fire extinguisher left in on the passenger side.
The relative lack of storage space has a positive side too - it's a deterrent to buying useless souvenirs along the way! http://www.fordgtforum.com/forums/showthread.php?14684-The-perfect-car-for-shopping&highlight=