The constitution clearly believes those impeached should suffer the consequences of their actions through both a political and legal judgement. So does article 2 section 3 preclude the derailing of a legal judgement by precluding presidential pardons to those impeached?
I would say that they would unless someone tried to charge him for the crimes he committed in relation to the Ukraine, because that's what he was impeached for.
If they charged him with income tax evasion, collusion with the Russians, human right violations for throwing Mexican kids into cages, then, no, he could get a pardon to cover those things because he was never impeached for them.