I am planning a trip to argentina in March. Traveling with friends for 2 weeks and then about a week on my own thereafter.

My plan with my friends is to have about three days in BA before flying down to spend 10 days in El Calafate, El Chalten and Ushuaia. I'll then have about 9 days on my own and I'm torn about how to spend my time. My thoughts are one of the following options...

some more time in BA with a short trip into Uruguay (suggestions in Uruguay)?

More time in BA with a trip up to Iguazu falls (have heard visas and border crossings can be tricky)

More time in BA and a trip to Salta (have heard it is beautiful but also heard train to the clouds is not operating).

I guess I'm open to other suggestions too. Any advice is appreciated!

Uruguay: You can do a full day visit to Colonia, 2 hours by ferry fron Buenos Aires, and return the same day, it's a good option.

Iguazu falls: You need al least 2 days if you travel by plane, i don't know your nationality, maybe you need visa to enter to Brazil, because you can visit the falls at both sides (Argentinian side is better)

Salta: It's amazing, you have a lot of activities to do and great places to visit. It's true, the train is not working, but you have Overlands (special trucks, fully equiped) whose do the same way of the train.
Ok, I hope this information will be useful. Have a good trip in my country!!!