I can see him being a bit more reasonable if a proper deal is made. I think that 20th Century Fox is going to have to give up a lot to the Walt Disney Company/Marvel Entertainment, but it can be done. If Perlmutter continues to be unreasonable, the Walt Disney Company can just shift Marvel Television over to Marvel Studios or ABC Studios.
I would find it hard to believe that the Walt Disney Company would say no to giving up the live action X-Men television rights in return for things such as the Fantastic Four film rights, 20th Century Fox giving up their cut in X-Men merchandising, giving up distribution rights to the Star Wars films and their ownership of A New Hope, a cut in the profits of the show, etc.