as long as you can still make money, don't even think about retiring early, I know early retirement is everyone's dream but who knows what will happen next, you have to maintain your grades and productivity so that you stay healthy and respected by people.
Well, if you love your job don't retire early since you're not just working but also enjoying it. Otherwise, think if it's still healthy for you to stay or maybe retiring early is the best decision to do. It doesn't mean you'll do nothing after since you can still seek for another source of income alternative to working 8 hours a day. It can be being an entrepreneur so you holds your time, your profit and most importantly you're the boss.
Anyway whatever your decision, what matter is you plan for it and it's not so sudden. As you've said, if you're still capable to work then do it because we'll never know what lies ahead.