I think the "waste" would be minimal, insignificant really. And besides, even on a cool day, you still want dry air on your windshield. Ask me how I know...
But ignoring the "why" and going straight to the "how," you'd just wire a switch in the dash to the wire attached to the top of your compressor. Turn the switch off, the clutch won't engage, and the compressor won't run.
Turn the switch on, and it will cycle normally.
But really, I don't think you "should," even though you "could..."
Two cents...
Robert