Succession to the throne + Jude's mortality

I was wondering... During the coronation ceremony Eldred said he felt the call of 'the land of promise' so he decided to abdicate. Jude had said before it is an euphemism for death in faerie. So does a Fae king have to die for the succession to occur? And does that mean that Cardan and Jude will die to pass the throne to their future heir? 😭

Plus there is the fact that since there is no canon specification about that, I think, Jude is immortal not only if she doesn't leave Faerieland, as said for Val More, (thing she won't ever do, as showed in how the king of elfhame learned to hate stories) but also so long as she is High Queen since she is closely connected to the earth. But if she abdicates (and let's say she doesn't have to die to) she will get older and die as soon as she steps foot in the mortal realm? I can't imagine her and Cardan in such a situation. 😢