Sorry to be a little OT here but Sue...if you ever need an agent to get your little ones thru customs for you or anything, I can get you the number of a guy I have used before in Atlanta when I imported from Hungary this summer. He was excellent! He retrieved my 2 yorkies from Air France, took them thru customs, took them to his kennel, cleaned their cages, let them eat & run around for a while (after being cooped up for over 24 hours!), and then took them back to the airport for their flight on to me in Nashville later that night all for around $150. It was well worth it! The pups arrived to me in tip top clean carriers and smelling A OK! they did NOT smell like dogs that had been travelling for over 30+ hours! They were not skiddish like I thought they would be either. This kennel was came highly reccommended to me and I thought I would pass it on if you hadn't heard of it before so that if that need ever came about, you would know that it existed. Let me know if you want to know the contact info.
As for shipping during the cold...I know that Delta just denied shipping some chinchillas INside the US this past week around the Oklahoma area because of the weather in Colorado. Chinchillas are acclimated to below what dogs are even. Not sure how the international flights work on this though.