Yeah I agree with this. Also, if your relationship survives being physically apart, it's very likely pretty strong.
Also, these are going to be the best years of your life, trust me. You will never, ever again be surrounded by so many people your own age, with a degree of freedom and free time, who are all pursuing basically the same goal. It's also where you will meet people that you will form lifelong friendships with, and make contacts that will serve you the rest of your life.
Spending those years in a quasi-state of "marriage" will hinder your ability to meet people and experience things. I say this not knowing your girl at all, so it's not a comment on her in any way. I'm not saying break up with her, but living on top of each other during this time feels limiting to me.
My two cents and it's worth exactly what you paid for it, which is nothing of course.