Frosted Airframe, Cold Engine, and Cold Battery
I always carry an empty 20L PVC drum with me, and use that to carry hot water from the town,farmhouse or wherever you can get it. I always carry a small PVC watering can too, which makes the aiming of the water a bit more accurate.
Transfer the warm to hot water into watercan, and pour onto the top of the wing about 30% back from the leading edge. Water then flows both ways, usually onto you too if standing under a high wing a/c! It's amazing just how well 20L of water cleans off a Cessna's wings. You do need to be sure that it hasn't refrozen on the wing or in the control surfaces.
With regard to that cold battery and engine, think about this. Fuel doesn't vaporise well in cold carbys, and a cold battery has less cranking power. The combination often means lots of frustrating cranking, and often flooding the carby, and flattening the battery.
Again - hot water to the rescue. Pour warm/hot water over the carby of your engine. It results fuel vaporising for a near instant start, and only requires a bit of uncowling in most a/c.
I've successfully used this on Cessna 152,170,180,182, and a Supercub. The 170 is a dream job - just slosh the water thru the aircooling 'hole' in the front of the enginecowl, which leads under the crankcase, and aft to the carby. It's been foolproof for over 10 years with my old bird.
Scaping ice off wings is a quick way to cause damage.
happy days,