He states that his original plan was to use the orb/anchor to enter the Fade and remove the Veil. In the fires of the raw chaos that followed he would restore his old world. Not sure how he even would survive the fires but I'm pretty sure nobody else would. Think how everyone looked at the Conclave after the explosion and then magnify it across the world. He definitely expects you to die in whatever he has planned. That's why he consoles himself that he is giving you and everyone else a few years of relative peace before he pushes the doomsday button.
If you do Hushed Whispers he is quite intent on discovering if what you experienced really did happen. If you appeal to Dorian as a witness, Solas disapproves. If you just say you're sure, he's okay about it. Have never been sure whether he assumes Dorian could have fooled you about the time travel or that he doesn't like the fact that more than one person can verify the truth about what happened. It is a pity if you did Hushed Whispers you couldn't remind him of the fact that you have had a glimpse of what the world would be like without the Veil and it didn't look good at all, even if some people were able to live through it. Mind you that was only through the Breach gradually growing larger. I think if he took it down all in one go, then the impact would be much more abrupt and devastating.
I have a theory that he is banking on the world returning to a pre-elf time, when there were only spirits and then building from there once more, with may be the ancient elves in uthenera also surviving to repopulate. If he and the other evanuris were originally spirits who became material (like Cole) then you don't truly die but return to your spirit form and gradually regenerate. He said his friend would do this but would not have the same identity as before. May be he is thinking that will be what happens with the evanuris, they will return to a more basic state. However, with Solas who knows. Even if I was in favour of his plan, which I'm not, it doesn't give me a great deal of confidence when he says "I have plans", since his plans never seem to have worked out in the past as he meant them to.