I see your point from a purely theoretical standpoint, but in the practical domain, you better be able to put power to the pedals to hold position in that 100mph wind. And given your powermeter doesn't record negative power, you'll still get average power greater than zero, as well as greater than zero calories expended to maintain your position.

The difference we're getting at to a degree, is that you're choosing to ignore the micromotion of the pedals. There is velocity at the pedals from the inching back and forth. Yes, the backwards velocity is negative, but the rider isn't producing that negative velocity, it's the wind. You aren't storing energy by rolling backwards that you can recover rolling forward.