GF of 4 years gave me ultimatum. Either we move in together this upcoming year or she’s done. How do I handle this?

For background, she’s a great girl and our relationship is pretty easy going. We split bills, she cooks all the time, gets along well with my family, etc. But there’s something about moving in and giving up a little more of my freedom that makes me want to run for the hills. I spend a lot of time on personal hobbies after work and worry she’d try to take away from that. How would you guys approach?