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.
