He doesn't marry her. Hell, he didn't even mention her in his friggin' last will and testament.
I think the bigger wonder/worry is: What If Eva Braun got pregnant?
She isn't mentioned by name, but he acknowledges her in his will as his wife
"I myself and my wife — in order to escape the disgrace of deposition or capitulation — choose death. It is our wish to be burnt immediately on the spot where I have carried out the greatest part of my daily work in the course of a twelve years' service to my people."
It is my opinion that Hitler would likely have stepped down as Fuehrer at some point, or perhaps remained the "honourary Fuehrer" and had another be his Reich Chancellor and no longer take part in government.
But it is without question that he intended to retire in Linz and marry Braun at some point in his life.