If you can't take the cat, it's good the owner has found a way to take meow-meow with her. Too many owners just abandon their pets when they move.

If you don't feel you can talk with the owner, by all means write her a note. Tell her just what you told us, that you have shared much with meow-meow over time and will miss him greatly--that you hope it will be possible to say good bye to him before she moves him away. Be sure to give her the best phone number for reaching you days and nights.