It's also not 1970 anymore. There's a prophalactic pill, there's morning after pill, and there's freedom of movement between states. Women are capable of exerting self-responsibility over their reproduction, and they are not helpless victims.
If you have money, or a network of help, and a safe home situation...
It's easy to say "everyone in a regressive state should move". It's easy to say "everyone in a regressive country should move". Not everyone has that option as readily available as you might imagine.
The GOP is working their hardest to send everyone back to 1970. Or further. 1850 looks pretty good to them.