Trump supporters will vote for him whatever happens. Impeachment or lack of it won't affect their vote.
It's the people in the middle that you need to vote for you if you want to become president. Trump swung a lot of them his way in the last election. I'd be surprised if he swung them in the next election, and not just because of the impeachment.
I know a lot of people who voted for him last time who will not vote for him again, having seen him in action. They are seriously worried about things like trade tariffs, a potential recession, coverage of pre-existing conditions being repealed, and the general lack of accountability of the Trump administration.
If the Democrats field an electable candidate (without the complicated past that Hillary had) then I suspect Trump will lose heavily.
But who knows what will happen between now and next November?