There are so many confounding factors that it's not even worth trying to pinpoint the 'chance' he experiences significant deleterious effects (or death). Most of the data is from March when the scientific community knew little about the disease and little about how to treat it.

For example, many deaths were an indirect result of blood clots which led to embolisms and stroke; we now know that COVID-19 has this adverse effect, so Trump will certainly receive anticoagulants/thinners so it would never even be a risk factor.

There are also a variety of genetic factors, including blood type, that have been shown to have an effect on one's response to COVID-19. Many 'fat' and 'unhealthy' people have walked away unscathed as some 25-year-olds die or are unable to exercise after the virus. It's a mystifying disease.