I prefer to wait a little and ramp up impeachment hearings during the election runup. Let the election cycle be dominated by Trump having to defend his crimes rather than simply tweeting out a new outrage to distract everyone.
Otherwise you are right - impeachment won't get past Moscow Mitch, who can actually control what evidence is presented to the Senate. The flip side is that by not at least doing something, Democrats lose any ability to say it's wrong, because silence implies consent. Hence why I think they should force this stuff to stay in the news cycle. Hearings can do that, because the news will otherwise move on to the next outrage in search of clicks and ratings if not forced to keep looking at one thing.