Here's my idea...
Elsa finds romance. But I realize that Elsa can't fall in love with just anyone. They kinda have to be a kindred spirit. Maybe her new love interest could have summer magic as a contrast to Elsa's winter magic. It could be the whole love-hate opposites attract kinda thing where Kristoff kinda makes fun of the new person in Elsa's life and Anna says...
Anna: NO! I will not! I don't think you should be making fun of him Kristoff. He's pratically Elsa's boyfriend.
Kristoff: Anna what are you talking about? They hate each other they fight all the time!
Anna: Yes! But very passionate fights! It has all the signs of a classic love-hate relationship!
And another piece of dialogue could be this.
Elsa: I loathe you!!!
Ben: I loathe you!!!
Elsa: You're a REAL CHARMER YOU KNOW THAT!?
Ben: And who are you? The Dowager Empress?! I NEED SOME AIR!!!
Elsa: I AM THE QUEEN OF ARENDELLE!!! (To Anna, Kristoff and Olaf) Omigosh I am CRAZY NUTS ABOUT THIS GUY!!!
Anna: Told you so Kristoff.