there is one other wildcard i want to point out regarding the pandemic, and that's the death rate. in 2016, trump did much better with older voters than clinton.
this is the graphic i need right now:
(https://www.pewresearch.org/politics/2018/08/09/an-examination-of-the-2016-electorate-based-on-validated-voters/)
55% of the population in 2016 was over 50, and it's the demographic he won; he lost the 45% of the population under 50.
you could be looking at over 200,000 dead people by election day, almost all of them over 50. it's easy to make the obvious conclusion that the virus could push trump out in a different way than is currently being contemplated.
i think you need to be careful with that for two reasons, though. first, i'd expect biden to do better with older folk, and we don't really know the breakdown of these deaths. if it splits evenly, it's a wash; if it actually hurts biden more, and it might given that the polling i've seen actually has biden ahead in the 55+ group, then it could even reverse the key swing demographic biden needs.
the second thing is that biden seems to be polling worse than clinton amongst gen xers, which is the group i'd consider myself a part of (although i'm the last gen xer, being born in 1981). in 2016, we saw a millenial/x coalition against the boomers. in 2020, the boomers actually seem to have swung to biden, but at the expense of potentially losing gen x. that could be important to trump, if gen x ends up voting at the highest proportions, even as we realize that the population numbers for gen x are much smaller, something that is not unforeseeable given the virus.
i don't have this data; this is a speculative post, i'm thinking out loud. but, in a close election, 200,000-250,000 dead seniors could be a deciding factor.