I remember arriving on a crisp winter morning to find the C-172 covered in frost and spending some two hours scraping off the frost between the rivet lines. Taking off I had a good look at the ski area in the ravine past the runway.
The wing that day wanted another twenty knots.
Subsequently I kept two cans of windshield washer fluid in the car. Not for use in icing conditions, but for frost removal, you really do have to get the wing and tail sparkling clean.