Even having Tyrion by her side I don't think will help either - if he does join her in earnest, it'll almost feel like a betrayal to his character in order to advance the plot of another who's had so much time invested in them but still fails to be compelling in any way.
Or maybe GoT will completely pull the rug from under us and have Tyrion's arc be the slow realisation she's not worthy and the time of Targaryen is truly over?
His character arc finished in the last session. His motivation was to be accepted by his father, which completely failed and backfired hard. Him being in the box for the whole trip, was a rebirth metaphor and the start of a his new arc.
Varys told him, that people like them will always only be on the side of rulers, but still be able to change the world for the better. Tyrion loves politics and he is completely fine in being a counsellor. He just finally needs someone, who he can truly believe in.
Dany's string of bad decision and failures was also important. She needed to learn, that you can't just rule with good attentions. She was surrendering herself with warriors, slaves and merchants, who have no idea of politics. Here story to this point shows, shows the importance of politic, if you want to manage people and power.
Tyrion's and Dany's arcs fit together like puzzles pieces. I also could see Snow being the last piece and becoming her admiral against the White Walkers.
The series will end like World War 2. Everybody uniting against one opponent. But just like history, the alliance will only last until they achieve their goal. Then the Known World will fall back to the power struggle of man.
