I just got back from Iguazu. We decided to save money and stay at the 100 a night Grand Crucero rather than shell out 400 usd a night for the Belmond.
It was stunning, and we just did the Argentine side...Im not paying Bolsonaro anything, so no Brazil.
Buenos Aires' nightlife has gotten even later. I recommend Flux Bar in the Microcentro as its the only bar that starts before 1am. Sitges does open early but its really only a lesbian bar before 1am.
A final note, Buenos Aires shuts down completely on New Years Eve. No Gay bars open, no special parties, no nothing. You can walk in the middle of a freeway. Deader than Id imagine Pyongyang would be. We eventually found 1 straight bar with some befuddled expats to ring in the new year. Actually it wasnt bad, but BAs NYE scene is amazingly dead.
If youre not staying at the Belmond, you need to be at the park gates by 730am to avoid the lines inside the park. You can do it in about 4 hours.
cabs are easy and relatively cheap in IGZ. The town has no Gay nightlife that I could discern, but was still fun enough.