I am cautiously optimistic
She has become more and more independent over the last couple of seasons and we can see she is very much a lone bird even when she is amongst other people and that kind of ending would be realistic for her. I think her and Sandor have bonded as well as we saw her choose to save him in the battle for Winterfell so I would actually like to see them both ride off together as a sort of assassin duo. I am not sure how realistic that is going to be though because we have got the Cleggane fight to come and even if Sandor wins I worry if he will survive his wounds.