I don't see any US ULCCs getting into the discount international wide body long haul market any time soon. This is already saturated going east with airlines like NAI, Condor, and WOW or west by all the random Asian carriers (spend some time at LAX). The profit margins are already too thin, and the financial risk is too high. Now narrow body to South America? That I could see. Doesn't Sprit already do a ton of business far south of the border?