Go to Autozone, Kragen, what-have-you and find an oil plug with slightly larger diameter threads. Then re-tap the hole (very carefully) to the new, larger, size. I dont think the drain pan would be nearly thick enough to put a heli-coil kit in there, and JB Weld is way over-rated (I would expect the plug to fall out before the next oil change).
The only cons I see to re-tapping with a larger plug, is that the dealer might try using the wrong sized wrench on it, but I expect even a dealer technician could figure that one out. It beats replacing the oil pan, and I'd trust it far more than JB weld.