Oh he!l your talking really freeken cold. I gotcha. How about making a resirculating chiller like some people here make, with a pond pump.my concerns are with hooking up to an outdoor faucet, creating an icy driveway, draining the hoses, and general cleanup after use.
Interestingly enough, I never had much luck with chilling in a snowbank. 40+ lb of boiling liquid takes a long time to chill via this method.Why would you need an immersion chiller when you have things like snow banks, and below zero wind chill?