It's an ounce of prevention that can save a lot of money on repairs and replacements. Newer 'streams like ours use PEX for plumbing pipes which is a bit more forgiving than copper. If you keep your Airstream in a heated space or live in it full time as I do, winterizing isn't necessary. However, when the temps fall, you'd better double check that you've got power, propane, etc. fairly frequently. Don't ignore it for weeks expecting it to be fine. Of course here in Virginia we normally get the worst cold weather in January and February, so you could watch the temperatures closely and hold off on winterizing until it's needed. Even then you still have alternatives:
I-95 South or winterize!
I do have a winterizing kit and a 12 volt
tire pressure pump that can blow the lines through the water intake. I can open the low point valves, get the lines drained, pull the plug on the water heater, empty the white, gray and black tanks, and have everything done within 30 minutes in a blizzard. Our fair city has three or four 24 hour WalMarts, so after removing the water filter and setting the water heater bypass valves, I'll be able to buy a gallon or two of RV antifreeze (if needed) on short notice too. (not that vodka won't work in a pinch... but then the dog won't be the only one tempted to drink from the toilet...
How close are you to your Airstream when you aren't using it? In the back yard? Last minute winterizing is possible. Stored 30 miles away - blizzard and roads are impassable? Winterize it ahead of time. (In Virginia 3 inches of snow turns 90% of drivers into raving lunatics, they just ain't used to white stuff.)
BTW there are a couple of threads on the forum with complete "how to winterize" instructions and pictures. Be familiar with the whole procedure ahead of time and have the necessary supplies at hand. That reminds me, I'd better look at the EB's water heater and low point valves. It's slightly different than the prior unit, and I don't need ugly surprises.