So I made a post a bit back about using air as insulation. Came across this article today, and it seems like it might be even better, but durability/flexibility/cost may be killing features. anyway, thought I would let people know.

its a foam panel with a vaccum in the foam, rated at r60. The first link shows them shipping a snowman from japan to the middle east with no cooling, surviving purely due to the insulation.

Here is another example of them shipping a cooked steak 400km and having it still hot on arrival. From the looks of it the panel seems like it would be very portable