I don’t know. You’ll have to do what’s best for you, but if I were in your shoes I’d wait at least a year until you’re sure your son has fully adjusted to college life and and has a stable friend-group. Going to college and losing the family home are both huge transitions, especially for kids who have lived mostly in one home growing up.
I think about the many threads on CC from sad/lonely/disoriented freshmen who haven’t found their place in college yet. I’d want to know my kid has found his footing in this new stage of life.