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You're very on-point when it comes to the variance in growing conditions - this is something we definitely wanted to address. I live in a zone 7b (in Northern Canada) - but it's coastal and mild: good luck growing what they do in North Carolina -- another 7b!
Definitely second your recommendation to start with potatoes. They are one of my personal favourites. I grow them pretty much all year long here. As soon as I get a few sprouting in the cupboard, I'll prepare a fresh pot of (home-mixed) soil and plant them in a bucket. This way, I get a bucket of potatoes every month. They store well if you cure them, and require almost no care.
Another one of my low-maintenance favourites are strawberries and chives. I grow them together, and they keep producing babies, so they make for an easy filler for empty space to keep the soil alive for the next planting.