The Supreme Court cannot overturn Heller without overturning Obergefell. The Court ruled as fundamental both the right of an individual to own & possess arms and the right of an individual to marry a person of the same sex. However, Heller’s holding is based on a longer history and a stronger foundation than Obergefell's holding.
I.e., if Obergefell stays at the party, so does Heller. It is a marriage pronounced by the Supreme Court.
57 South Texas Law Review 215 (2016).

If the rule of law is to prevail, Supreme Court decisions that hold that a right is fundamental require obedience by lower courts.
Yet in the wake of the Supreme Court’s Heller and McDonald decisions that clarify and protect Second Amendment rights, federal and state inferior courts have been engaging in massive resistance.
81 Tenn. L. Rev. 673 (Spring 2014).