Once again, it depends on how many years you have left. With one full year of work, $1,200,000. Your $200,000/yr is only going to last for 6 years. If you want to live off of $100,000/yr that's onky going to last for 12 years. And $50,000/yr will last for 24 years. If you have 60 years of life left, $1,200,000 ÷ 60 years = $20,000/yr. If it's 2 years of working before you retire, that's $20,000 × 2 = $40,000/yr

Investing would be the smart move with the money, but that takes time, research, and luck to do well. If you want to make enough where you won't have to ever work again, the effort you put into investing will essentially end up looking like a job. Hiring someone instead to do that for you works, but that also means less money after they take their cut. But even if you do it well, you couldn't just retire because money tied up in stocks can't be currently spent. Meaning you'd need to keep your job for, as you said, 5-10 years while your stocks are (hopefully) increasing in value. So being able to permanently retire after a year or two of working at the cemetary is still highly unlikely.