Doubling salary post-tax will at the very least put you at a 50% savings rate, and that yields a time from zero to financial independence of 16.5 years. Assuming historically-similar stock market returns and a safe withdrawal rate of 4%. This relationship does not depend on absolute numbers beyond those stated above, only savings rate.
Most likely you'd not be starting from zero and having a positive savings rate already. Whether you'd be comfortable doing this is a different question. Many would never be, and hence never completely comfortable retiring.