One thing that Republicans have done with their Obamacare "repeal" attempts whether they are successful or not is set the precedent of using reconciliation to alter it. No reason I can see that Democrats can't use it to create a public option, or at least more generous subsidies (paid for by higher taxes) if they regain power in 2021.
There already is precedent:
https://en.wikipedia.org/wiki/Health_Care_and_Education_Reconciliation_Act_of_2010