Mourinho is not a stupid man. I think he knows that going to Saudi Arabia is somehow the end of his career. It doesn't have to be, but it feels like it would signal that the last years are about to come for him as a coach would usually prefer to spend the most of his energy in one of the European top leagues.
But the question is still interesting and in my opinion not answered yet. What would Mourinho do if he gets an amazing offer from a great club in the next few days or weeks? He loves challenges and I don't know whether he is as much about money as other people are.
There is no one (especially a coach) who does not like money in any case if an offer comes to him, but if the amount is not too large than the offer made by a great club. Of course Mourinho would choose to coach a great club rather than have a career in a certain league with a club that is not great, but if the offer could be quite tempting for him. I think he will also go to Saudi Arabia if someone wants to use his services as a coach who is experienced and also great at football.