Long Distance With A Marine?

My boyfriend of a year and I have thought of so many options. I’m from Germany and he’s from the States. He wants to be a Marine and my parents want me to go to college in Germany. My boyfriend and I have agreed to try long distance for 3 years. He would come see me once a year and I would come see him 2-3 times a year.
Marines, do you think a long distance relationship could work?
We love each other very much and are extremely committed to each other. We plan on getting married and having our own family.
What do you think?
Also, are visitors allowed on base? For how long can they stay? Can they spend the night?