October surprises to save the Republicans:
A major foreign policy “coup”, such as Russia, China, Iran and or North Korea having revolutions and pro-western leader coming to power. Russia withdrawing from Ukraine, or China granting independence to Taiwan and/or Hong Kong would be just as good.
The Democrats and left-wing media admit that Covid19 was never a serious threat, and the lockdowns were never justified. The Democrats would never admit the sun rises in the east, if that clashed with their view of political correctness.
A peace agreement between Israel and the Palestinians, that is endorsed by the Arab League, all of whose members promptly recognize Israel. The Palestinians are unlikely to give up their claims, so this is unlikely.
Trump dying of something other than Covid19 (assassination would help the Republicans the most), such that Pence is the nominee for president, and Trump’s “deplorables” support him as their man’s chosen successor.