"It can be occasionally closed due to a Winter white out."
That is a given, is it not?
That is equvilent to "I can't flush my toilet if my son shoves all his toys in it and then trys to flush it!"
You can't predict the unpredictable! Am I wrong?
The effect of a "Winter white out" would likely throw a wrench into the works, but likely would be short lived. It would not be the death knell (call) of the POW mill!