My wife and I just completed this 4 night cruise on the Ecstasy to Cozumel, Mexico. The dates were January 3 through January 7th.
ARRIVING
We arrived at the Carnival terminal about 1:30 from Hobby airport via a limo from Ambassador Limousine. (Carnival doesn't provide shuttle service from Hobby, but they do from George Bush International.) There were hundreds of people everywhere. I thought getting on would take some time, but we were on board by 2:10. The people were very helpful and worked to keep the boarding process going. You can leave your bags with Carnival employees at the curb, or you can carry them on yourself. We chose to leave them at the curb. One by one they arrived by 5:30.