If you, like me, believe it's nearly impossible for a huge winery to make interesting wine, then this event is not promising. I've encountered some of them, and the best I can say for most is that they can be decent QPR:
Adega Cooperativa De Borba CRL Their top wine, with a cork label, is nice Herdade dos Grous MODERN
J. Portugal Ramos Vinhos HUGE
Jos Maria da Fonseca Vinhos S.A HUGE
Aliana HUGE, decent QPR
Sociedade Agrcola E Comercial Da Quinta Da Aveleda S.A. Good vinho verde
Bacalhoa Vinhos de Portugal S.A. Quinta da Bacalhoa is a well-known Portuguese cab, if anyone wants that; used to be better
Campolargo make a decent pinot noir
CARMIM HUGE and very mediocre, at least what I've seen
Casa Santos Lima HUGE, but try their Touriz, a blend of Touriga Nacional and Tinta Roriz; used to like it, but haven't seen in a while
Do Sul HUGE
Sogrape Vinhos S.A. HUGE
Esporao Wines and Olive Oils MODERN
Symington Family Estates MODERN
CARM MODERN, has decent reputation