WA state sort of does this. Min wage is set annually by a formula that includes things like cost of living. It's not perfect but WA min wage is usually one of if not the highest in the US.
So the Overton Window is actually further over than it may seem.
Edit (the deets):
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Beginning mid-September each year, L&I will make a cost-of-living adjustment to the minimum wage based on the federal Consumer Price Index for Urban Wage Earners and Clerical Workers (CPI-W). The new minimum wage will be announced on Sept. 30, and take effect Jan. 1.