Hey there’s also Canada! We don’t have San Francisco salaries but Toronto tech blows away the EU. With a job offer, you can get a visa in a few weeks.
So why move to Canada?
Get Canadian citizenship after 3 years, and become eligible for TN visa, which is not subject to any lotteries or quotas.
That's not been my experience when hiring. Serious candidates from serious schools don't seem to have any issues getting it.
Saving the same percentage in a higher CoL place gives you the option of moving out or retiring anywhere, including a high CoL location. You don't have these options if you make a lower wage at a lower CoL place.