Missouri summers are generally hot and humid but the year was rather mild.
Thompson@Morgan have a seeds of a dahlia cut flower mix that grew and bloomed for me.
I plan to store the tubers for an earlier start next year. - Jim

Buddy Dean of Hilltop Dahlias would be a good source of info for your growing conditions there. See link below. Or take advantage of the dahlia growers at Carolina's Dahlia Society who will also be much more familiar with NC regional growing conditions. Their contact info:

Lonnie Walters
245 North Hills Drive
Hendersonville, NC 28791
(828) 891-9507
~ dlj683@morrisbb.net

They would undoubtedly have other sources of info for dahlia varieties that would grow successfully in your area. Dahlias can be quite variable from place to place, year to year even. That's why they have Trial Gardens all over the US. I'm sure you can find some beauties that will add to your cutflower bounty.

Here is a link that might be useful: Hilltop Gardens