Faced with a possible impeachment, megalomaniacal dictator type like Trumpo da Clown would generally do what he could to eliminate the threat, would he not?
How difficult would it be for him and his cronies to change laws and procedures to prevent impeachment?
Considering that impeachment proceedings start in the House of Representatives, and conviction occurs in the Senate, and it's written directly into the Constitution, damn near impossible. Trump has no ability to tell Congress what they can or can't do.
But, yeah, as long as the Republicans control both houses of Congress, the only way Orange Joe is going to get the boot that way is if he does something so egregious that the Republicans realize that it will cost their party politically in a major way if they don't act. Or if Trump does something or multiple somethings that so dramatically breaks with their ideals that they feel compelled to get rid of him. The Republicans don't have the guts to stand against him for less.
As it stands, I think the next 2 years are impeachment-proof for Trump. Most likely, in fact, he'll survive the full 4 year term. The Democrats will win a few seats but will lose more than they win in the mid-term Congressional elections in 2018, securing even greater Republican control of Congress. Republicans will fight any efforts to redraw Congressional districts and will continue with voter-suppression activities, since changes in districts and greater voter participation is unlikely to benefit them. The balance of power in the Supreme Court will shift to the conservatives for at least the next 10-15 years. The Democrats will rally and will manage to win the Presidency in 2020, but Congress will remain in Republican hands, and 2020 thru 2024 or 2028 will be similar to the Obama years, with Congress and the President fighting each other continually.
All of this assumes that we don't have another major unexpected life-changing / world-changing event that drives public sentiment in one direction or another.