The fact that you are gripping down on the club already means that you have altered the effective swing weight already. Physically shortening the shaft and gripping back up the shaft will have a marginal effect on current feeling imo. Shortening the shaft 2 inches will probably remove a few gms of counter-balancing (about 1.5-2gms per inch of the thick end of a 45" 65gm shaft and a bit for the grip).
I don't believe you will notice any significant difference in balance!
Do it either immediately or whenever you decide to re-grip it.
