what he wants", well, for the most part he CAN. Except when he wants to do something he could easily do when he was 30, like shovel the entire driveway in under 10 minutes or do a bunch of yardwork, etc. But Dad's still active. He rides a bicycle for two 30 minute sessions each day--once in the AM, once in the PM, and if it's nice outside, he'll ride around our block, which is roughly a mile and has several small hills, making it harder than riding on a stationary bike. In fact, his cardiologist asked him about exercising and Dad said he got "60 minutes of bike riding in". The doctor said "oh, in a week?" and was surprised when Dad said "no, every day". For the most part, Dad "feels fine" physically. It's the mental part I occasionally worry about.
As for trying to stop him from shoveling snow....hahahahahahaha. Yeah, no. Dad is going to do what he wants, and nobody, especially no CHILD of his, is going to dissuade him. The best I can do is gently suggest he not do something. I was talking about this today at a church party; my good church friend went through the exact same thing with her dad (though his health issues were slightly different), and another (casual) friend is going through it with her dad right now. Men of a certain age were raised to be self sufficient, and they're reluctant to give up any of their personal freedoms no matter what the consequence to them might be.
I'm dreading the day Dad's unable to drive himself anywhere...I don't see him giving up the keys easily like Mom did when she was no longer capable of driving. And we don't have public transportation around here and I can't imagine Dad getting an Uber, especially since he won't give up his flip phone. Right now, Dad remains an excellent driver, better than people half his age, so I'll worry about it when (if)* that day comes.
* (I only say "if" because there's a woman at church who's in her early 90s and still driving, and driving well)