I am heading to Charleston SC in Feb. towing my 23 ft. sailboat along the West Virginia turnpike (Interstate 77). I have never towed in mountains before and am a little concerned. The turnpike has one large mountain that I understand the locals call Freefall mountain and suggest all drivers wear parachutes. I have a 4 wheel drive Tundra that is afraid of heights. Should I drive in 2 or 4 wheel drive going downhill and what gear do I choose. Any other feedback will be appreciated.