He would probably be pushed away by the fact that all her friends disliked him, and drift back towards his old life and the friends that survived. Draco would live in his old family home where Hermione was tortured, and she wouldn’t ever want to go and visit him there because of that. And she would get some boring position at the Ministry, and Harry and Ron would nag at her about Draco, and they would never see each other between Harry and Ron’s disapproval and Draco living at the Malfoy Manor and...and...and they’d eventually realise they just weren’t compatible, and split up – and he’d find some more suitable pureblood witch to marry, and she’d end up a workaholic spinster living in a tiny flat with only a cat for company.