Well, if you want me to be specific: I could easily take a year or two off. I’m not sure I could take ten years off. That’s our financial position.
Then I think you should take Omar’s original advice and look for a new job while you have the current one.
No hard feelings, but if you’re sure about your decision, either just quit today or give notice today. Speaking as someone in charge of hiring, I have a company to run and would like to begin looking for your replacement sooner than later. While you may not need this job, I need someone who wants it.
Unless you are back in the workforce within a year, you may never get back in. Are you comfortable with that?
Because that way, he wouldn’t get to wait for just the right moment – when the boss has just told him to do some stupid, horrible, probably illegal thing, that is somehow absolutely necessary to the career of the worst problem-causer there. THAT’s the best time for him to ‘put in his notice’, effective immediately.
Even if that situation never comes up, knowing he has that option might just make it a lot more bearable to stay there for a couple more months while job-searching.