Let's see about that landslide first, I'd say. Plenty of time and an October surprise to come. (I read the CDC is already gearing up on getting states ready to start working with vaccines - which will be a complete danger as nothing has been fully developed yet, but hey-ho! Or maybe they'll just go with that wonder vaccine developed in Russia by Trump's best pal.) And if there is no landslide loss (or even a win), the Democrats might not take back the Senate either.
Trump will anyway have made the Republican Party reconsider its political orientation. After the Obama wins, they concluded that they needed to connect to different demographics more, like hispanics. That would have been one of their reasons to oppose Trump's candidacy. But Trump showed that that's not the only possible road to victory, and so the GOP leadership might also have reconsidered the type of candidate they want or can accept. They might be pretty happy now with someone who's a lot like Trump, just less stupid.