Libertarians should not even focus on winning congressional races let alone presidential. The real ticket to success for the party is the state legislature.
If Libertarians take over state legislatures they can turn their state into a fair fight by following the lead of Maine. Since Maine has Ranked-Choice Voting along with proportional allotment of Electoral votes libertarians have a chance to win the state. This will also generate familiarity with the party to the public in order to eventually win in congress. The only other way the party gets a President in office in the years to come is if a sitting President runs as a libertarian in their second term and even that is a long shot.
Article from r/Libertarian: For a Free Society