There are more people that leave the grass normal length.
We don't change the height when we mow.
The reasoning is, grass gets energy from the sun.
If you cut it short, it takes that much longer in the spring get gather that energy from the sun.
As far as cutting the grass short to keep snow mold away, I'm not entirely sure about that.
As long as you don't let the grass go 6-10+" and keep it at normal height or just a hair shorter, you're going to be fine.