L.D.
Hi D.! Here is what we have done while traveling with our daughter since she's been in our lives. We drive to the airport, but use a parking facility called Park Fly and Ride instead of parking at the airport. You can reserve your spot on-line before you go and it is much much cheaper than parking at the airport for any length of time. Indoor parking is available as an option as well, so you don't have to deal with snow.
You park at the facility and then they provide you with a quick shuttle to the airport. It's easy breezy - you are dropped right at your terminal. When you return to the airport, you call them after you get your luggage and they'll tell you where the shuttle will pick you up. This is generally at a door close to the baggage claim. (Your baby can ride the shuttle sitting on your lap.)
I highly recommend this option for traveling with car-seated children. It has worked very well for us! A link to the service is provided below. Hope this helps!
http://www.parkrideflyusa.com/?source=google&002=1070...