I am winterizing my first hive, and I need some advice in what type of insulation to use. I am trying to decide on using the pink fiberglass housing insulation inside black contractor bags, or foam insulation board. I live in the Northeast US, where winters usually get down to 10-20°F with about 2 feet of snow on average. During the coldest part of winter, we might get subzero temperatures for a good week, around -10°F. I am going to do a quilt box (made of a medium box with a screened bottom and filled with pine shavings with a few screened ventilation holes in the sides), that sits on top of a shim to give the bees a top entrance for when the bottom entrance is covered by snow.
So, I am curious what people use for insulation in climates similar to mine. Also, is the gabled Flow roof just fine to leave on through winter?