I'm having a difficult time committing to a quick trip to Montevideo before we leave BA. Right now we have 8 days in the city (with day trips), then 4 days in Mendoza. We get back to BA on 11/30 and leave for Santiago 12/3. Should we spend a couple of nights in Montevideo??? Should I purchase the boat tickets in advance? I would want to be back to BA on 12/2 so that we don't have issues with missing flights, so it would just be from 11/30-12/2. Any tips would be much appreciated!!!