This is easy. Turnout on both sides will be high. That means blue district/states will be bluer, and red districts/states will be redder.
There are probably more blue votes out there than red votes, but the blue votes are concentrated in California, New York, Massachusetts, etc. (and not even with all districts in these states), while the red votes control about 30+ states, and the great majority of counties.
If that’s correct, it means minor changes in the House (maybe lose a few, maybe gain a few), and a very bad year for the Party of Satan in the Senate (6 - 7, or maybe 10 or more seats becoming Republican). A 61 - 39, or even a 62 - 38 Senate is not out of the question, paired with a 245 - 190 House. More likely 57 - 43 / 230 - 205.
But the election is still 5 weeks off. That’s enough time for the picture to change two or three times more.
Five weeks is a lot but lets not forget early voting has already started.