If you pay attention class, I mean like try to the learn as the professor goes, and take good notes, and spend a little bit of time everyday getting work down, you will find that you will have plenty of free time. It's really about time management and getting shit down when you need to get shit done.
There will be weeks where you don't sleep, finals/midterms etc, but there will be weeks when you don't have anything at all to do. I made it through with a 3.6 and i went out 2-3 times a week and during the winter skied 2-3 nights a week. It's not easy and you will spend alot of time doing work, but you will also have alot of time to goof off and have fun.