i drive my stang in the snow... I have blizzak tires for the rear and use my regular tires up front. I also put 100 lbs of sand over each rear tire (in bags of course like you said). I really don't have any trouble unless there is a major amount of snow. The thing that gives me the most trouble is i have a 6 so i don't have a t-lok. This causes me to fish tail some in heavier snow. I sure a t-lok will help the cause but having a GT might make it worse. I'm sure you'll be fine though as long as you drive with a little common sense.
2002 Mineral Grey GT, 5-speed: MGW short throw, JLT CAI: SOLD
2002 Electric Green V6, Auto: SOLD