"Well, when the president does it ... that means that it is not illegal" -- Richard Nixon (1977)
"Well, when the president does it ... that means that it is not illegal" -- SCOTUS (2024)
That leaves impeachment as the only legal remedy, which you've correctly identified as not a possibility with the current congress.
His two previous impeachments don't seem to have slowed him down, so it seems unlikely that a third would be any different. Not to mention his felony conviction.
The actual legal remedy is impeachment + conviction by the senate. That hasn't happened yet and seems unlikely unless he actually loses the support of his own party.