I have quilted a jumbo queen on a regular domestic machine with a 4.5 inch throat. It wasn't easy, but I got it done.
Have you looked at Marti Michele's methods of quilting in sections and splitting batting? It might be a good place to start. You start with a strip of batting only in the center section of the quilt. This allows for less bulk going through the throat of the machine and makes it a bit easier.