Very interesting read. I'm a newbie to the Stocker world so I have been "lurking" around here and came across this. I work for an injection/blow molding company that manufactures REUSABLE ice packs. And...they make different temperature ice packs that you could adjust your beer that you are "intaking" (I see what you did there...
)
here is a link.
https://arctic-ice.com/
Take a look at Chillin Brew for a little cooler than Ice and Tundra for "dry ice" like temps. Beware...Tundra will freeze your beer!
This is NOT dry Ice. But it is a phase change material that works very well it freezing things.
I'm just home for lunch so check this sight out and I will be back later to discuss.
Later, CF