There was a silver age comic that did something like this (although it only lasted a short time, not years), by having a volcano with a chunk of kryptonite in it, or something. Basically, Clark had just enough of his powers to do Superman things around the island, but when he tried to fly away, the kryptonite-laced smoke from the volcano kept him grounded. Or something like that.
I love the idea of an L&C Robinsonade!
If my muse and my schedule are kind, then maybe... Well, anyway, I hope someone takes it up.
