They didn't forsee the encirclement, therefore didn't plan accordingly. & the cauldron was only a 15 mile perimeter, doubtful any army could have pre-predicted the exact locale of the cauldron & put in place ahead of time all that infrastructure.

On the other hand, they should well have pre-predicted the horrible weather, & perhaps some runway snow clearing equipment should have been sent in ahead.

The spring offensive on flat terrain surrounding Stalingrad is the more interesting strategic contemplative theme.