Another option besides using larger bolts (which may reduce door alignment adjustment ability) is to install helicoils in the stripped holes. The original bolt size is 3/8-24 and the next readily available size is 1/2-20, (7/16-20 bolts are available, but a little harder to find) so you'd loose 1/8" overall movement without hogging out the slots in the hinge bars. Helicoil kits are pretty easy to use, and come with the proper tap, inserts and an installation tool.
You could theoretically remove and replace the nut plate from the door, but access is really limited. I wouldn't want to try that. Too many opportunities to get it wrong or mess something else up.
