My opinion on the bee cozys;
To me it seems that the insulation in the cozys would prevent the suns heat from warming the hive up.
Have you cold inside you clothes?
Sun warms only some hours if it shine. Bees wintering does not depend on sun heating. Bees produce the heat they need. Insulation hinders heat escaping. Night is cold.
Using these 20 cozys, I found that they covered the upper entrance I use, which meant if I wanted I would have to cut a hole in the cozy for proper ventilation.
It is needed, but if you have a mesh floor, upper entrance is not neeed. But bees like to use upper entrance to cleansing flight. It is short way to warm cluster.
When we have insultated hives, we do not need any wrappings. However many beekeepers do that because it is their habit from dad to son. I use geotextile to protect the entrances from wind, birds and snow