Adelitas is open almost 24 hours a day; however, there aren't many chicas there in the morning hours. Most chicas don't start work--and most bars don't open--until early afternoon. After opening most bars are very active until 2am or later.
When making plans don't forget this is the Christmas shopping season. The wait to cross into the US is very long these days. (Returning at night will be quicker than crossing during the day.)
You didn't say if your flight was at 3am or 3pm, but I'm guessing your flight is at 3pm. Hitting TJ that morning isn't what I'd recommend. Your best bet would be to hit Tijuana the night before. Then cross over and get a room in the US.