Long story short - United Mileage Plus/TAM messed up my itinerary and cancelled one of my confirmed seats, and now instead of having a full day in Rio (after returning there from Foz de Iguacu at what was supposed to be 8 am on 1/4) before a 6 am departure on 1/5 GIG-JFK, I only have 12 hours (arriving from Iguaca to GIG at 5:45 pm on 1/4 with 6 am next day departure). I've heard the hotels at GIG are absolutely vile and not worth the money, but I don't want to keep my reservation at the Sheraton Rio (and pay for roundtrip taxis in traffic) just for a few hours in bed.

Does anyone know if GIG stays open all night and allows people to camp out on benches? Alternately, does the TAM lounge stay open and possibly sell one-time access passes? Or is there a Delta/Skyteam lounge in a different terminal that I can access even though I'll only have a TAM boarding pass (I am Delta Silver Medallion but have some one-time lounge passes).

Thanks!