In Cherokee, it depends on what rivers you'll fish. The most common are the Oconoluftee and the Raven Fork. Both of these are relatively large for NC, with plenty of room for casting. Some of this water is on Cherokee tribal land, for which you'll need a special permit to fish. You don't need a NC fishing license on this land, nor will the license do you any good.
The reason I mention this tangent is that there are actually 2 types of water, the first is the regular stocked permit water, and the second is the special "trophy" section on the Raven Fork (and small part of Oconoluftee) which is catch and release only. The fish in this section are very large, with lots of fish 20" and over. If you fish here, a 9 ft 5 wt would not be out of place at all. The same rod would still work on the regular stocked sections, although most fish you catch will be in the 11-13" range here, with a few smaller wild fish showing up, or the occasional large fish wandering in from the trophy section. However in this section I'd prefer the 8 1/2' 4 weight.
Actually I usually Euro nymph, where I'm using a 10 1/2' 3 wt rod, but if you're not up on Euro nymphing, you can ignore that for now.
Getting back to more normal NC small stream fly fishing, including some streams in Cherokee such as Soto Creek, Straight Creek, Bunches Creek, etc. the 8 1/2' would probably work. The issue you have in NC is tight overgrown streams with little casting room. My favorite rod for this fishing is a 7 1/2' 4 wt, which IMO is just the right length for fitting in tighter quarters. A longer rod will lead to more snags and tangles. IMO the really short rods though such as 6' is a mistake because for really tight spaces, you need reach more than casting ability, to do little flips and chucks.
Some sections of Wilson Creek are quite open and would take a 9' rod, but there are some tight sections as well. Another area I used to like to fish, and now take my son to, is Stone Mountain park NC. There are a couple tributaries here that are quite small, with East Prong Roaring Fork being the primary. Again there are some sections that work just fine for my 10 1/2' Euro rod. In fact sometimes a longer rod is actually better in tighter quarters for simply reaching and lifting, which is how you end up fishing with nymphs a lot. But for tradtiional casting, it takes up too much room on many places on that stream and again a 7 1/2' is about perfect. But an 8 1/2' will work as well. We used all 3 of these rods at Stone Mountain on our last trip there and each worked where we fished them.
If I could just choose one rod to fish in all of NC, it would probably have to be my 7 1/2' 4 wt because that can get me in anywhere. For example it worked fine for some Shenandoah native brookie streams on our last trip up there, and there are quite a few of these types of streams in NC as well. But honestly I'd be miserable if you told me I couldn't Euro nymph any more with my long rod.
