For those of you convinced the polls are somehow clueless - if they were off by the same margin they were in 2016, the NYT projects Biden would win 335 electoral college votes.
Election night itself could look pretty bad for Biden - the swing states that will report results the earliest happen to be the ones that are more likely to fall to Trump (Florida, Arizona, North Carolina). If Biden wins either of those it should be over pretty quickly. But even if he doesn't, his numbers in Wisconsin, Michigan and Pennsylvania are staggering - far beyond anything Hillary Clinton had at this stage. Those states may not have final results until next weekend because of their bizarre mail-in ballots rules, but it's hard to see Trump winning all of them. Biden could lose every other swing state and still take the White House with those three.
Ultimately it will come down to Pennsylvania, which Trump cannot win the election without. No respected poll has him winning. At this stage, his best shout there genuinely seems to be winning other states early on to make the race close, and therefore persuading establishment Republicans and key cabinet members they should back him on his inevitable claims of voter fraud. If he doesn't have any momentum and it looks like a done deal for Biden, they'll quickly abandon him and leave him to complain on Twitter for months before he slopes off in January (I would guess overseas). Especially if the Senate itself flips Democrat (which also looks likely at this stage)