When could we retire early?

You can retire early when your annual expenses (including taxes) are about 4% of your investable net worth. Some say more, but few say less. So for your $180K, that means you could retire now if you can live on $7.2K/year.

Assuming this isn't acceptable, your first question comes into play.

What would be the best strategy at this point to retire early?

Forgive me for first stating the obvious, but the best strategy is whatever strategy suitably maximizes your salary or wage income and your investment returns and minimizes your expenses. These are the three factors that get you to the magic number. First choose the one you have the most control over and exercise that control. Then move to the second and then the third in order of control. If you can tolerate a little risk and a lot of volatility, I recommend that you look into Mechanical Investing to maximize your investment returns. The Foolish Workshop board is the best place to start.

1HappyFool