My thought is that if you are going to adopt another cat, you should do it very soon before Max gets used to being the only cat. My Artful Dodger was very much the alpha male, though a small cat, and was still harassing other cats within a day of his death from multiple disorders, he was that bad. The cats who coped with him best were two large, softy silly males and a very agile Siamese female, all senior like Dodger. The softy males simply rolled over and then ran to me for hugs which made everything better. The Siamese shot out of reach and looked disdainful. The others went through hell and two ended up living in the hall cupboard. I know that Dodger would have enjoyed being the only cat, but I also believe he would have been very lonely. It was as though other cats annoyed him but life wouldn't be as much fun without them.

Do you know someone who fosters and would let you "try out" having another cat for a few months?