Trump could be removed from office without impeachment
A special body can be appointed to determine if Trump is fit to serve without him being impeached.
Two students at Yale Law School have been doing their research and have determined that Congress can remove President Trump by a little known clause in the Constitution, one that doesn't involve Vice President Pence and a majority of his cabinet sending a letter to Congress about his fitness for office.
That 25th Amendment scenario itself is extremely unlikely anyways, because Trump could simply fire them before they got a chance to do it. This actually happened in an episode of House of Cards (spoiler alert).
Here are the two other ways Trump could be removed by Congress:
1) Appoint a panel of independent medical practitioners to judge the health of the president.
2) Appoint a body with no medical expertise because the 25th Amendment's wording is very vague to allow the House to interpret the criteria for the President being "unfit to serve."
Congress can even appoint its own members on this panel. This would allow it to enforce its own criteria for "presidential fitness."
Per their Time article:
"For example, Congress could deem the President “unable to discharge the powers and duties of his office” if he is unable to be trusted with classified information by intelligence agencies. Congress could even use the threat of removal to exercise additional leverage over the President’s actions."
Senator Lindsey Graham even made an argument on the Senate floor in the 1990's.
"So, the point I'm trying to make is you don't even have to be convicted of a crime to lose your job in this constitutional republic if this body determines your conduct as a public official is clearly out of bounds in your role."
Of course, he was making the argument against former President Bill Clinton at the time, but his logic still stands.
While they claimed such scenarios have never happened before, they said it was still legally possible.
In order for it to be more of a reality, though, Congress shouldn't be afraid to exercise creative solutions should they be forced to.