Actually, "If no candidate receives a majority of Electoral votes, the House of Representatives elects the president from the top three presidential candidates who received the most Electoral votes. Each state delegation has one vote, which is determined by the 12th amendment of the U.S. Constitution."  So enough third candidate votes will get you "one of the above."....in your scenario......Clinton, Johnson or Trump.  We've, of course, seen third party candidates play important roles in Presidential elections by draw votes AWAY from the candidate they most "resemble"; to the advantage of the candidate they least resemble.......George Wallace, Ross Perot and Ralph Nader come to mind..... 

Hopefully, someday we'll see "preferential voting" become a reality.......your vote for candidates "in order"... and, should your first choice be "out of the running", your second choice receives your vote.  Such a change would hugely benefit third party efforts.  ...therefore, it's unlikely .....