I have an investment policy statement with specific rebalancing bands. When those bands are reached, I will act and rebalance. In the case of a higher stock market that means lowering my stock allocation to the ISP target.
My annual spending is based on a fixed % of asset value at year end. If the market drops before year end, then I will lower my spending for next year. But the market at this point is so much higher than last year that it will have to drop a lot for me to spend less in 2018 than I will in 2017.
Have a plan, stick with it.