The foal will be fine and I wouldn't stop at all except for fuel. The faster you get them home and unloaded the better. Even if the foal doesn't nurse much it should be okay. They deffinately can stand for 15 hours. If you stop 3 or 4 times for fuel and let the foal nurse then it would be fine as long as there is room and the foal doesn't get squished.
There's nothing like the Rockies in the springtime... Nothing like the freedom in the air... And there ain't nothing better than draggin calves to the fire and there's nothing like the smell of burning hair. -Brenn Hill