I'd like to see the Republican Party split. Have the Trump, "populous" folks create their own party while the old style Republicans form another party.
Then the problem of moderates being "primaried" would vanish. The Republican power base would be weakened (it's probably already weakened) so the Democrats could relax a bit.
Being more relaxed, maybe the Democrats could solve their own internal strife, between moderate and far left, by splitting into two parties as well. We would then have 4 parties.
In the past, I haven't been an advocate of third party presidential runs; like from Green Party Jill Stein (2016), or Ralph Nader (2000), but if the "winner take all" power blocks of the current two party system are not there anymore, a multi party system becomes more viable.
Bernie Sanders was smarter than Ralph Nader as he didn't run as a third party candidate taking votes away from the Democrats. When he lost the Democratic primary, in 2016, he supported Hillary Clinton and in 2020, he supported Joe Biden.
Especially for Congress, we could use more parties that are viable.