It's usually recommended to aerate shallow during the cold months, to avoid the supercooling effect. What you are shooting for during winter aeration, is to clear an area of snow/ice, NOT turn over the entire water column. If you have clear ice with no snow cover, you may be fine without aeration. I won't chance it, and will crank up the diffusers whenever I get extended intervals of snow cover.
Haven't needed to do that thus far this winter....
