Go for it girl - be as crazy as Starlagurl. You wont regret it.
I highly doubt if you will be able to check in for your flight the day before. I am trying to find out if Aeroparque has a left luggage office. As it's just a domestic airport, it may not have this service. I'll let you know what I find out.
If it does, take the airport shuttle from Ezeiza to Aeroparque. Once there, change into the best clothes you have, then take a taxi to downtown Buenos Aires and have a great meal with steaks bigger than dinner plates. Corrientes Street is where it's all happening. Keep in mind that Porteņos dress well, so look as nice as you can.
Many years ago I arrived in Buenos Aires after a long ride in the back of a lime truck. We arrived at 5:00 pm on a Friday and the only place to change money was the American Express office in Harrods. We were so scruffy we were almost thrown out of the shop. We actually had to beg to get the the exchange counter, and we were escorted there as if we were extraterrestrials.
It's not quite so bad now, but think Rome or Paris!
See if you can find a tango show that fits your needs, not too classy as you won't be suitably dressed. Probably something in Boca would be the thing. Boca is about a 20 minute taxi ride from the city centre.
http://en.wikipedia.org/wiki/La_Boca. Remember, travel by taxi is very cheap and safe, so use them to get around. This tango show looks quite good, and they even have a package that includes a meal:
http://www.moebius-tango.com/detalle.php?id=126&h=13,111When you are done, just go back to Aeroparque and flake out on a bench. Make sure the airport doesn't close down at night, as it is located right next to the elegant residential district of Palermo, and I'm sure there are no night flights.
Keep on truckin'
Cheers
Martin
.