@Boyceaz I think numbers 2 & 3 could definitely work (I'm interpreting 're-do' to mean expand the court & appoint sane ppl, who would repudiate the immunity case if given the opportunity).
The only way I can think of where legislation could work is by limiting SCOTUS' jurisdiction to prevent them from hearing cases having to do with presidential prosecutions, say.
But none of these will rehab the current criminal cases, I don't think. US v trump is the law, and will probably outlive trump.