Just a cautionary note: Cheney is still alive. Trump’s parents also lived to ripe old ages (93 and 85). He may be right about his “good genes,” in that respect at least.
You’d be surprised how long people can survive these days with outrageous levels of internal disease. My mother had multiple serious health problems and a long, long history of lousy lifestyle, but even when it came to multiple infections, sepsis, hospice and palliative oxygen at the end, her heart just would NOT stop beating for days and days. It was amazing.