Nancy,
Thats a great looking specimen plant! It looks like theres plenty of room on the current cork board for the plant to grow and as long as it isnt breaking down, I would leave it. I have a similar sized digbyana on an old board of wood that I think I will have to chop up soon because it has outgrown its board and is climbing onto itself. The board itself is also getting soft. Ive had several excellent commercial growers and hobbyists tell me that orchids can actually kill themselves by getting too big on a mount that is too small. Since your mount is in good shape with plenty of room to run, I would just enjoy it and let it ramble for a few years. Good growing!