AEP to MVD is a 45 minute flight. Whether or not you get a snack probably not a big worry. MVD-GIG is 2 hrs. 40 minutes if you fly non-stop. I've had domestic flights much longer than that in Brazil, on TAM and Gol, and seldom got any more than a drink and a non-descript ham and cheese sandwich. All airlines are cutting back. AEP was not a bad airport, though my camera was stolen while I was there (my fault for not watching closely enough as I moved things between 2 carry-on bags). Hope you have some trips out of Montevideo planned. The city is not that big. It's a far cry from Buenos Aires (and some people like that). Some very good restaurants. I stayed at the Sheraton Four Points, which was nothing fancy, but was comfortable. Do read up on the city's history in advance. I flew Aerolineas Argentinas from MVD to AEP and on to El Calafate and Ushuaia, so can't help you with Pluna.