At this point you might as well change Veigar's R to an ultimate skillshot version of Anivia's Q
No matter what else you do rangewise or even spell wise, its not going to make Veigar have a decent winrate again. Right now his R feels out of place completely with his kit. This combined with making his W like a 3 charge system with slows on impact would be the only real way to make him cohesive.