I thought long and hard about just that.
25 years ago I ran all sort of projections using QuickBooks retirement planning software. Realized by living simple and saving like mad we had gotten to where it was a gamble, but retiring seemed feasible. I could go back to work if I had guessed wrong.
Retired at 54 with a small government pension but most important, the pension included lifetime family medical care. This made retiring much less of a gamble. Started spending my IRA at $750/month (allowable back then IF you signed for a flat rate for the rest of your life) - to cover the period before I could draw SS.
That was 25 years ago. Things have worked out fine. Savings balance is about what it was when I retired if you adjust for inflation. That and two properties, is going to make a decent inheritance for the kids if we don't spend it all on in-home care in our final years.
I love playing Gentleman Farmer, even if I'm making hardly anything from the apple orchard. It's a great retirement hobby, as it was for Dad and for his father before him. This sure beats sitting indoors watching golf on TV like some retirees my age. Life is good.
In my opinion living simple and retiring early is a better alternative to working until you drop.