I work in the area you speak of, but have never seen the Airstream you're talkin about.
Winterizing is not a big and bad as some make it out to be.
First, find a spot to store it. Back in the day there used to be a farm in Lake Zurich that is no longer there. It's now homes and a forest preserve.
For me, mine will be in the driveway.
After that is taken care of, get some tire covers, RV antifreeze and wash and give it a good Walburnizing.
Drain all the tanks. Place some of the RV antifreeze in all the drains, and pour a gallon into the fresh water tank. Turn on the pump and let each faucet run for about 5-10 seconds. This should be long enough to not only get the antifreeze in the lines, but also in the drain pipes and the holding tanks.
Make sure the hot water tank is empty. There is not a real huge need to have antifreeze in the hot water heater if you have successfully drained it and used the bypass if so equipped.
Take the batteries out and place them in a location where they will not be exposed to freezing temps. Deep Cycle batteries HATE freezing temperatures. Lubricate all the latches, hinges and give the interior a real good cleaning, removing any food, liquids, perishables, etc.
That pretty much covers it in my book, others feel free to add....
Two other schools of thought I am sure will come up...move to the south during the winter (not always and option) or keep the heat on in the unit over the winter (can be costly).