I bumped into another window cleaner in the barbers the other day and he was moaning about not being able to work for the last 8 days due to frozen equipment and broken filters....he also doesn't work when it's raining....
Some guys just never learn(he's been window cleaning for years too)....
Be prepared or prepare to fail....
1.IMO every wfp cleaner should have the ability to heat their water whether its via immersion,diesel or aquarium heater and/or some form of heater overnight in the back of their van.this will prevent 99% of equipment problems in freezing weather.
2.save an emergency fund of at least 6 months bill money in case you really can't work for whatever reason(weather,injury,illness,etc)
3.work in the rain,customers get used to it and most won't mind(skip the ones that do).