Now that winter is back. It is not imperative to cover hives right away. If you can do it now, great. The bees are ok in this weather. But the hives should be covered in the next week or so.
There is a snow storm on the horizon for Tuesday. You never know if we are getting an inch or a foot. So watch the weather.
I hope the beekeepers in the central and northeastern MN got their hives covered. They did have a couple days notice of impending winter.