That depends on whether it's the grip screw bushing that's stripped or the frame.
A decent gunsmith can extract the bushing and install a new one, but if the frame is stripped that requires using a special over-sized tap to re-thread the frame and install a special over-sized bushing.
I rather doubt that many local gunsmiths will have the tap, but it can be bought from Brownell's, along with over-size thread bushings to match.
If Kimber will pay shipping charges that would be the way to go, but since you did the damage they might not be willing. Shipping costs can run well over $50. one way.
If the frame is aluminum they probably won't pay.
But if the frame is steel, I'd think there's a chance the bushing was over-stressed at the factory since it would require more torque then just a little to strip either the bushing or the frame.
In any case it costs nothing to contact Kimber. Perhaps just for good customer relations they might agree to send you a shipping label or pickup notice.