66,
Lots of good solutions given, I have used all three, Toothpick, larger screw, fill & tap. Tooth pick works great, as it gives easily, and will not allow for a lot of pressure on the screw hole sides.
Here is how you do it. You take your lovely wife out for dinner, Enjoy a great meal. Tell her how wonderful she is and how without her you would be a total dork. Then pay for your meal, pick up a couple of tooth picks (un scented...LOL) on your way out.
If she catches you fixing your bike with the tooth pick, just tell her " see, I told you I was a dork without you, and I stripped out this screw hole when you weren't with me". She is gonna LOVE YOU !
Bulldog