I think a lot will depend on Trump's opponent. Possibly the main reason Trump won last time out is because Hillary Clinton simply wasn't inspiring enough to middle-ground voters either, nor to wavering Republicans, who therefore decided in the end to back their man. Put a half-decent candidate up against him and Trump's unpopularity among the majority of Americans will end up telling against him. If the mid-terms go against Trump too, then the next two years will see him achieve little, and it might not be too surprising to see someone who's actually capable of working with both sides making a breakthrough.
*That, and a few key states breaking for him, so that he could still lose the popular vote by a hefty margin while winning the Electoral College.