Not really “even-handed”; since the GOP is going to gain Senate seats, that means that most people would have to split their votes, which is NOT going to happen. Why would vote for GOP Senators and NOT also vote for GOP House seat candidates as well?
It’s the math...Senators are voted on statewide, Reps congressional district wide. There may be many suburban or urban districts that Dems win, but that’s only a percentage of the overall state vote (and may be a small percentage depending on who actually comes out to vote - look at the liberal loon who won the district in NYC where only about 10% of registered voters came out to vote - but she still won). So it’s not about splitting their votes, it really comes down to turnout.
“Why would vote for GOP Senators and NOT also vote for GOP House seat candidates as well?”
I’m not smart enough to know if that holds up mathematically!