I've never understood the congealed conventional wisdom which says that when Roe/Casey are overturned it'll be a 50 state issue. There's nothing preventing Congress from outlawing it. There's nothing to prevent the Supremos, as Crazy Tom "abortions are only okay when I perform them" Coburn would like them to do, from declaring legal abortion itself to be a violation of the rights of blastocyst-Americans.
If the Supremos do away with Roe/Casey, it will be a long hard and constant slog to preserve abortion rights anywhere in this country.