Here in western IL, a deep + medium would be the BARE MINIMUM to get a colony thru the winter.
In your location, it may be the 'norm'
BUT.............once you are thru the winter, give it a second deep...........a single is NOT enough for a productive queen.
As far as removing the 'extras', do it BEFORE the flow stops for good, on a warm day when they are flying well; that gets the 'field bees', which tend to be old, grumpy, and VERY aggressive, out of the hive.
If it were me, I'd leave one FULL medium plus whatever is in an unfilled 'partial' for over-wintering; take only one full medium off (unless you have a late flow that fills more, of course).
Just my $ 0.02.......