I have been trying to research info on Coppernose Bluegill and how cold the water can get before they die, with little to no results.
How far north can you stock them and just how long can they live in adverse conditions before dying?
I see a lot of hatcheries in Oklahoma, Texas, Arkansas that raise them, well the last few years it’s gotten bitterly cold, does this mean they all die? Or are they more hardy than that

I've got 3 ponds in a 100 mile area, north of I-70 in KS stocked with CNBG. Recruitment is low compared to NBG. For supporting Bass (LMB) in KS anywhere but "maybe" the very SE corner, NBG will out-produce the CNBG.

We are just north of I-40 and CNBG work well for us. Not sure of anyone who has CNBG near the OK/KS border from my circle.

There have been several threads about the northern limits for CNBG. I believe most of the threads have settled on the latitude of I-40 being about the northern limit for CNBG to THRIVE!

There are people that have them north of that line, but most of the reports suggest that common BG will outperform the CNBG in those regions.

See this

See pg 3 of this - https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=552435&page=1

https://forums.pondboss.com/ubbthreads.php?ubb=showflat&Number=483801&page=1