Try and learn a little Spanish the basics are easy and they appreciate it if you try. I found the Culture in the two capitals pretty similar. I think in Argentina they eat later and get ready for plenty of meat eating. Argentina has the best beef in the world!

I had some very "big" and late nights in both countries but you are right it is considered bad custom to have more than two bottles over dinner in a group of four. I was traveling with two mates I think we had two bottles in 10minutes.

You will have a great tip enjoy every minute!