Two Four more guys I would like to add:
Captain James Cook - One can make the case that his newfound hot-tempered attitude, and the state of his mental health by the time of his third voyage, caused his death by making an ill-fated attempt to kidnap a Hawaiian chief. Nonetheless, I think there was a decent chance that he would've still died on his third voyage but had he survived the third voyage, aside from a promotion (Commodore? double promotion to some Admiral rank?) and return to his role as Captain of Greenwich Hospital, I'd give him about five years (dying in ~1785 at the age of ~57). Also the fact that explorers also have a tendency to die within a few years of their final voyages/retirement.
Alexander Hamilton - I'm not totally sure how much the death of his son affected him but in his later portraits, you can tell that he aged quite a bit by the time he died. Would he go the way of Dean Martin or Theodore Roosevelt and die partially from melancholy due to the death of his son or would he die as a wise old man, weathered by his personal and political experiences in life (a bit like John Adams, at least from the HBO series)? I'll vaguely give him about twelve more years (dying in ~1816 at the age of 59 or 61). Much as I would like to have him live to the 1840s and 1850s and to give us a surviving photograph of him... (Adams was the only Founding Father to make it to 90 I believe, please correct me on that one).
Prince Thammathibet - Siamese poet prince who was heir presumptive (Front Palace) to the throne of the Ayutthaya Kingdom. He was implicated in affairs with either one of his father's queen or four of his father's concubines and was summarily executed as punishment in 1755/57 (alongside the woman or women implicated with him). Just ten years later, Ayutthaya would disintegrate due to a Burmese invasion while one of his brothers who eventually became king, Ekkathat, gave an underwhelming effort against the Burmese invaders, although what I would argue was typical in the beliefs prevalent during his time period (Siam was mostly at peace with Burma in the previous 160 years between 1600 and 1760). This means that I don't believe that Ekkathat was a terrible ruler (despite what mainstream Thai historiography has to say about him), nor if Thammathibet could've done a much better effort against the Burmese, but maybe the butterflies would've just been enough (at best, perhaps becoming a Burmese tributary state, the Konbaung invasions of Siam were inventible, in my opinion). Like most Ayutthaya kings, he would probably live to his 40s/50s (from the sources that I have, they don't list his birth year, unfortunately), probably somewhere in the mid-to-late 18th century.
An interesting butterfly would be that had the sacking of Ayutthaya been prevented, the vigor of the future Siamese dynasties (Thonburi and Chakri dynasties) wouldn't have materialized, meaning that how Siam handles the West in the 19th century this TL would be very unpredictable. Would Siam go War Doctor mode (Doctor Who reference) and done the same as they did OTL or would they (after surviving the 1760s Burmese invasions) fall into complacency once more and fall to the West or to another Burmese invasion (maybe even a Vietnamese invasion) later on in the late 18th/19th centuries.
King Ananda Mahidol (Rama VIII) - The 20-year-old king of Thailand, mysteriously found dead with a gunshot wound to his head in June of 1946. Thailand at that time was going through a brief resurgence of democracy, following the discrediting of the military, who had sided with Japan during WWII and was out of the political limelight in 1946. Rama VIII's death sparked a chain reaction, which included the resignation of a leftist Thai Prime Minister, effectively causing the end of post-war Thai democratic governance and a return of Thai military rule by 1947. Had Rama VIII lived, Thai democracy would've likely survived longer against military opposition, and at the least, delayed the return of a military government by a few years (in the long run, it would inflame further democratic sentiments in Thailand with a longer surviving democratic period). He would, in this alternate world, die at the age of 94 in 2020, following an 85-year-long reign (he was only nine years old when he became king in 1935).
Sources (third inclusion only):
Baker, Chris, Phongpaichit, Pasuk, "A History of Ayutthaya: Siam in the Early Modern World", 2017.
Wyatt, David K. "Thailand: a Short History (Second Edition)", 2003.
Lieberman, Victor M. "Strange Parallels in Southeast Asia, Vol I.", 2003.
