I'm in NH, and it gets down to below -15F/-26F here with lots of snow and stays before 32F/0C for the high temp for a good month. I use SBB on all my hives, but I also have varroa trays under all of them, so those act as a buffer to the cold air - dual purpose - wind buffer and allows me to do another check w/o opening the hives. I also have slatted racks over all the SBBs. If you are concerned about cold, you can either put a solid bottom board underneath for the tray (BetterBee solution), or use the SHB trap from Rossman, which is open below the tray, but just leave out the insert in the tray, so you can do hive checks.
As for the top, I use the shims from BeterBee with the plugs. They provide ventilation but also give room on the top of the frames, in case you have to feed dry sugar or want to add pollen patties. Don't drill holes in your boxes.
Using that combination all my hives (then 6) made it through this past winter.
If you want to gather honey, don't kick over the beehive. - Dale Carnegie