Somebody noted in another thread that the Constitution doesn’t require a President to be elected by a majority of possible Electoral College votes; he only requires a majority of the votes that were submitted. The precedent of this is 1864 when several southern states didn’t cast votes for obvious reasons.
So let’s say, as a hypothetical, that every state with a Republican governor declares that they are postponing their elections until things are “better”. And the states with Democratic governors go ahead and hold elections. The results would be a total of 291 Electors being chosen, with 266 of them committed to voting for Biden. That’s an overwhelming majority.
Let’s say the Republican governors are a little more on the ball and those of them in states where the polls show Trump winning hold elections. This goes better for Trump; there would be 427 Electors chosen with Trump getting 161 to Biden’s 266. That would still give Biden a clear majority.