In terms of pure fundamentals, MVD could probably support a flight to IAH. It's a growing economy, in many ways healthier than Argentina, and increasing in regional importance. It's also on the rise as a tourist destination.

The problem is that it's still a very long haul, and a double-redeye is not good for utilization. It's likely too far for the 321XLR, even though it's almost entirely over land and doesn't require an ETOPS routing.