Do you have a structured asset allocation/withdrawal plan for FIRE? If so, just allocate the lump sum according to that. If not, then there's your problem!
One option would be to do a bond/CD ladder that is long enough that you will no longer worry about losses in your equities, because you will have plenty of cash to ride out the drop in the market. The length of the ladder is based on your risk tolerance -- most people I think do 3 or 5 years, but my FIL did 7 years. Say 5 years for illustration purposes. The basic idea is that you take what you need for the next 5 years' expenses, and you put 1 year's expenses into CDs or individual bonds with maturity dates in each of the next five years; then each year when those mature, you use that money to live on, and sell enough stocks to buy another bond 5 years out to keep the ladder going. So say you need $30K/yr. To get started, you would take $150K of that money and buy $30K of bonds maturing in 2019, $30K maturing in 2020, $30K maturing in 2020, $30K maturing in 2021, and $30K maturing in 2022. When 2019 rolls around and you need the cash, your first set of bonds has matured, so you cash that in and live off of that money. At the same time, you sell another $30K (or whatever figure you think you will need) of your stock investments and buy bonds maturing in 2023, so that every year you just keep the ladder rolling.
Why does this help with market volatility? Because if the market crashes, you don't sell your investments to fund the ladder 5 years out. Instead, you just let your investments ride and continue to live off your bond proceeds for however long the crash lasts. And you don't have to worry, because you are fine for years! Then when the market does eventually go back up, you can take some profits and replenish your bond ladder to cover those years that you missed.
This is basically a psychological trick to manage fear of sequence of return risk. There's no magic in it as an investment principle -- you are just using a little of your money as a safety blanket to calm your fears, so you can free your mind up to invest the remaining money in the market and treat that money logically, without freaking out about downturns.