I'm a Virginian who has studied this incessantly. Prevent West Virginia's creation by butterflying away either 1) Lincoln's election, 2) the start date of the American Civil War, or 3) Virginia's secession from the Union after Lincoln's election.
The third one would be greatly preferable - it not only spares Virginia and Richmond the death and destruction of the Civil War, but the state's fledgling industries would not only stay intact, but have access to the vast resources of West Virginia, so with the post-ACW industrial boom, Virginia would be in a similar position to Pennsylvania, and flourish as the Keystone state did. Virginia would become a part of the greater BosWash a little over a century ahead of time.
As far as earlier PODs, regarding the Western claims, unlike the rest, Virginia did have a recognized claim to Kentucky - keeping Kentucky as part of Virginia, while a challenge, would undoubtedly make Virginia more important as well as larger - having access to both the Atlantic, the Ohio and Mississippi Rivers would make trade as important to the state as it did for New York. Also, with even more mountainous mostly plantation-free counties in the state, you also just nerfed any chance of Virginia seceding during TTL's Civil War.