worm cooling questions

[Brillo67]

Hello all,
So I have moved to a new place and where i am at, i cant really just set my still up on my back porch and make a run like i could before. My biggest thing right now is keeping my worm cold. What i did before was just fill my 5 gal bucket w/ worm with ice and water from my hose outside. If i want to do any runs i will have to do it inside on a new stove top model i am currently investigating designs. Would it be possible to keep a worm cool with dry ice or would that get too cold and freeze it before it makes it all the way through? Also, could i use a fan to cool the coil with just air flow?

Thanks for the help