Cesar asks about over-wintering 5-frame nucs in Styrofoam nucs.

I regularly over-winter 5-frame nucs, without difficulty.  Depending on
where in Colorado you live, our winters here are probably as cold as your
own, but we might have less snow.  We average about one meter (39 inches) a
year of snow, and usually have at least one consecutive week where night
temperatures are at least -20F.

Being covered with snow does not hurt the nucs, and may help them by
providing better insulation.  I think it is critical that they be packed out
with sealed honey and pollen by mid-October.  I use Carnolian stock and
think they winter better as nucs than Italians.  Upper ventilation is
critical and I use two 1" holes screened from the inside.

I have never tried Styrofoam, but know of others who have.  The Styrofoam
nucs I have seen are very tight and I would worry about that.  Bees must
have upper ventilation, or they will die.  I suggest you either find a way
of propping up the cover or drill small holes.  I have tried holes as small
as 1/8", and they have been successful.

Best of luck,

Lloyd
Lloyd Spear, Owner, Ross Rounds, Inc.  The finest in comb honey production.
www.rossrounds.com