If Roberts won't do it, and you don't want Leahy to preside, or anyone else who is affiliated with a U.S. political party, who ya gonna call? Queen Elizabeth?
How about just calling off the whole charade?
It's not a "charade." The guy was a criminal when he was in office, and he must be held accountable, regardless of the fact that he no longer is in office.
Remember that trump just totally ignored everyone who didn't vote for him when he was in office and just bad-mouthed them, and millions did not vote for him, considering that he did not win the majority vote in either the 2016 or 2020 elections. He would not even submit to Congress' lawful oversight.