A heart attack can finish off someone much younger and in much better shape in an instant. By his own admission he doesn't exercise, and he needs a golf cart to move more than ten feet at a time.On average, with average medical care in the USA. A man his age will live to 87 (11 more years).
But he is also very wealthy, not a smoker or alcohol user. He has a lot of factors that will likely mean living even longer than that.
I know he seems unhealthy, but from a doctor's perspective he is actually very well for someone his age. I wouldn't expect him to pass away anytime soon. All guys his age are eating unhealthy in my experience.