I wanted to bounce an idea off of the forum - As I look at my stock pile of cozies for my IMUSA (both 10 and 12), MSR, etc... I had an idea, of why not just bring 3 panels of reflectix with you, and wrap your mug there, and set a piece under and above it. And be creative, and find a way (elastic, velcro, etc) to seal the wrap around the body of the mug.
Granted it wont be seal 100%, but it allows more flexibility and maybe one cozy fits all approach.
Thoughts - or am I thinking to much on this one.