I am planning
4/22 pm arrive Ushuaia
4/23--4/25 stay in Ushuaia, join a 3-day tour, going to Tierra del Fuego, the lighthouse, sea lion island, #3 freeway....
4/26 am fly to Buenos Aires. Stay the next 3 days
4/29 pm fly to the Iguazu fall, Stay the weekend there
5/1 am fly back to Buenos Aires then back home.