Frankly, I'm not really sure what a" Balinese-style spa resort" entails. But it doesn't sound like something you do while the TV commercials come on. Do you have the background, or expertise to make this a go?
It seems to me that you are viewing retirement as getting up, chopping a cord of wood, then getting down to really doing some hard work. That idea usually last a few months. Sooner or later, you will realize you're not 50, thinking you're still 40, anymore. There is a reason for retirement, and it's not something bingo card manufactures made up. I don't want to squelch your dreams, but when you actually retire, take a couple of months off. Then figure out what will make you happy and how to go about making that happen.