Mix in ground speed to flight speed

I fly my plane in Auto mode without an airspeed sensor. Cruise throttle is 45% and on a still day it cruises at exactly 45mph.

If there’s a 10mph wind then ground speed downwind becomes 55mph and upwind 35mph which I have verified and makes complete sense.

Is there a way of mixing ground speed into the equation so downwind it backs off the throttle a bit and into the wind increases it so ground speed is less varied depending on whether it’s going into or with the wind.

Stall speed is much lower than 45mph so downwind with a bit less throttle would still be safe.