I know this has nothing to do with weather temps but maybe... The best packaged corals I ever received was from Colin (cbrennan4). He used medical specimen cups. I wish I took a picture of them in the box.
The cups had the bottom of cut clear solo cup to fit frag plugs with slits cut out on the bottom edges for water passage. They were then placed in tge box wit Styrofoam, newspapper and a heat pad (it was winter). They didn't budge in the box nor did they lose any water. The temperature was perfect too. Of course this would work for small frags, zoas and such but I liked the idea.
Jackie