When a state closes the interstate, the load stops with it.
Winter storms have shut Midwest interstates this season. A dispatcher who tells the driver to find a back road is guessing with someone else's truck. Back roads are not rated for the load, and they are where trucks get stuck.
Park it or rewrite it
If the road is closed, park the truck somewhere it can sit. Then write a new route, a new rate for the miles, and a new appointment. If the receiver will not take the truck on the new day, it waits.
Do not pay a driver to creep forward on a highway the state has shut.