Satoshi could have also mined later when difficulty was still not so bad and have other wallets people don't know about. So in theory Satoshi could have cashed out couple millions from his later wallets already and be living on some island in Caribbean.

It's definitely conceivable that he/she would not be so greedy as to touch the origin coins. It's enough to cash out couple millions from later wallets, buy some nice house near beach and live very comfortably.

Of course, I still think much more likely scenario is that Satoshi is dead or lost his/her private key.