Title is mostly relevant for getting plates to put it on the road. If it's going to stay on private property, then it doesn't seem to be required. They say they want a title for anything over 4000 lbs gross weight. You might be able to claim you did enough work on it to call it a homemade trailer.
The biggest concern is being sure it isn't stolen.
If you need to move it just hook up and go. Many times over the years my family or I have forgotten to renew trailer tags and have never been cited for it. It is purely accidental but nobody seems to pay any mind.