He's going to be a lameduck from day one, he's not going get his prefered cabinet picks, he's not going to get anything done with a narrow house majority and a 52-48 R majority in the senate, no court packings, no DC/PR Statehood. The Supreme Court is 6-3 conservative, they're going to dismantle the ACA, also the Democrats are going to get slaughtered in 2022/off-year elections.
The Democratic party is also going go in a state of civil war with radical leftists in the one side, and centrists on the other, now that Trump is not POTUS anymore/for now.
Then 2024 happens where Rs will have a favorable map for the senate, starting out with 3 automatic pickups (OH, MT, WV) and more toss-up races for pickings, possibly putting Rs with a 60 seat majority.
Enjoy it while it lasts!
The "lame duck" quality relates to the extreme age of Joe Biden. Yes, I expect Republicans to do everything possible to create gridlock so that anyone who wants anything out of the government will be obliged to vote R so that they can get the tablescraps that they want desperately at the great cost that Republicans connect to it.
The radical leftists that you mention are going to be obliged to make pragmatic choices.
The Republican Party is not distancing itself from Trump as
Republicans distanced themselves from the elder Bush in 1992 (OK, it was a tired act)
Democrats moved away from Carter after 1980 (losing big is not good for keeping control of the Party)
Republicans moved away from Hoover after 1932.
Trump did not lose that badly, but unlike the others he still has a personality cult that seems to have survived the election.
OK, governing isn't easy. Something always goes wrong.