Verified answer

Yes, people move in out of dorms all the time. You'll need to talk to the placement office who put people into the dorms they request. What is likely to happen is that you'll move in with someone who only has one roommate in whatever dorm is currently available. They will try their best to match you up with your top choice, but since you're moving mid-semester you may not be able to get that choice, but you'll get placed into one of their college dorms.

Blessings

So long as the school has spaces left in their dorms at that time, you usually can move in. Talk to housing now about how all that would work, so you can get things ready. Also, ask them how likely it is that a space would be available.

At some schools, the schools are actually over-enrolled right now, and there are more students who want housing than there are spaces available in housing. But spring tends to be a better semester for housing - there tend to be more spaces available than in the fall. So talk to your housing office now, and see if this might be an option.