Well, WillC, as I have found your articles all over the internet, and read with interest, I was so glad and curious to read your opinion for this plants future.
@grafiti4u, I feel WillC's expertise trumps mine, and it made me want to respond in a different direction.
The reality is, you are may be looking at a period of time, where you struggle a bit hoping for the best. If the plant is at the point of no return, I hope you will be considering what new plant you would absolutely be thrilled to try in it's place. Distract yourself with researching other big species you may find are even cooler than this old friend. There are some amazing indoor tall plants you could grow. A Coconut Palm, a Japanese Yew Pine, (love love) A tall Yucca, A tall Ponytail plant, Ficus Alli, (prettier in person), etc etc.
Just keep your eyes open, and your mind open to accept you may lose an old friend, but reward yourself, for a job well done with a nice big replacement, you will love just as much. Spend as much as you can on this one. Tall plants are expensive, but worth it. So, say no to the urge to pout, and give yourself something to celebrate, for the green thumb it takes to keep a Drac so healthy for 5-10 years.