Thanks to each who have responded.

By insulating, (I should have made clear) I mean more than wrapping with
roofing felt, which has much less than R-1 insulation value.  I meant to
ask, has anyone had experience wintering colonies in R-4 to R-16 insulation
of some kind?  Wood is R-1 per inch thickness.  Polystyrene is about R-4
per inch.  I am under the impression that bees don't get the shelter they
deserve in cold climates.

Cheers,
Kyle