Maybe substantive due process links the two cases in the most nebulous and abstract way, but fundamentally Roe v Wade is about a person's right to control their own body (e.g., nobody can force me to donate a kidney even if I'm a perfect match), whereas Dred Scott was about the exact opposite.
Edit: I also disagree that looking at where judicial philosophies lead is a bad idea. At the end of the day, the judicial system exists for two main purposes: 1) enforce contract law and 2) enforce the moral zeitgeist in the most fair way possible. If an inflexible judicial philosophy is unable to keep up with the morals of the times, we should consider revising the judicial philosophy. I believe this is considered fairly mainstream legal philosophy, and a big reason "originalism" is considered basically a sham by the legal profession.
Edit: I also disagree that looking at where judicial philosophies lead is a bad idea. At the end of the day, the judicial system exists for two main purposes: 1) enforce contract law and 2) enforce the moral zeitgeist in the most fair way possible. If an inflexible judicial philosophy is unable to keep up with the morals of the times, we should consider revising the judicial philosophy. I believe this is considered fairly mainstream legal philosophy, and a big reason "originalism" is considered basically a sham by the legal profession.