You are correct, you must be separated (living at different addresses) for at least 1 year and one day before you can file for an absolute divorce in NC, and one spouse must be a resident of NC for at least the 6 months prior.
As far as I know, (otherwise my STBX is in for a nasty surprise), one party (as long as the other party stays in NC) can reside out-of-state. It can make handling the Separation Agreement & Property Settlement more expensive, depends on the attorney.
And get the separation agreement (including property distribution, post-separation support, and alimony) signed before you file for divorce. Filing for divorce (or responding to a divorce complaint w/o asserting ED/PSS/Alimony as counterclaims) removes the right to petition a court for them.