I'd like them to get back together for his sake.
I feel like my Lavellan would eventually move on and find someone else and have a real fab life, and I want that for her. But I also horribly sort of want her to never move and just wait for Solas because I feel so sad for him. It's going to be complicated making character choices for her and knowing more about the situation than she does, hard to stay faithful to her character and not make myself really sad.
I would love it if they figured out some plausible way for them to be together. But I feel like there will be no easy answers. It doesn't mean I'm not willing to be surprised, but he seems to be someone they have plans to utilize for a while, possibly over multiple games (it did take 3 games of seeding Fen'Harel into the lore and legends and awareness before revealing hey, he was at your side the whole time...and maybe you even loved him), and his own words before leaving made it sound like things were about to go down and she would notice some consequences happening.
My Lavellan, this isn't her first relationship. But this one, this one is special. It hurts sharply and uniquely. The intensity of their emotional and intellectual connection blindsided her and the love and in my headcanon, physical side followed with the same force. She is a strong person and could eventually learn to move forward and maybe even open herself again in time, but it would be some time before she'd even consider it.
But if they can't be together, I want him to experience some inner peace, somehow. He is such a tragic character. 