The company I own is a mail order company that specializes in shipping live tropical plants and rather delicate little creatures year-round. Beacause of this I am quite used to shipping things far more delicate than hatching eggs and getting them there safely. I can speak from experience that thick insualtion will do nothing if there is no heat source inside the box and it is too cold outside. It is for that reason that we regularly use heat packs that can last up to 60 hours for shipping delicate plants. If a bit of common sense is used, shipping during cold weather is not that risky. Considering that we are based in Western Mass, we need to be able to ship in cold conditions for almost half the year
In fact, it is dumping on us right now outside and storm number three is coming on Sunday. Guess it will be a white Christmas!
Richard

Richard