I don't think Solas is a real god though, just a very powerful ancient elf. It's been hinted throughout the story that there is a big difference between how legends are told and how they actually happened. The Inquisitor herself is an excellent example of this. Walking around with a glowing hand will make for some impressive murals in the coming ages.
It's also interesting to note that a lot of these stories about the Dread Wolf originate from a society with different values than most of current Thedas. For example, Tevinter is regarded as an amoral society by most people in Orlais and Ferelden yet it turns out the Ancient elves lived in a similar society where people had slaves and Blood magic wasn't as bad. Solas comes across as an introvert who sees live in 50 shades of grey and is always curious to learn new things, willing to change an opinion when proven wrong. Qualities that would probably not make him a great supporter of the old ways
A codex entry about the Dread Wolf says " ..."
To me this actually sounds very similar to the mage/templar conflict in DA2 and DAI. Both sides have great power, are dangerous and neither of them is right. If at some point in the game, the Inquisitor was given the option to get rid of both threats by taking away their power, I think quite a few players would have chosen that option and it would probably have resulted in similar legends 
There are two things which I believe:
One is, as Arahnea suggested, that the old Elven Gods weren't really Gods but incredibly powerful ancient elves. Immortal, incredibly powerful ancient elves.
Two: Some of those immortal, incredibly powerful ancient elves are alive. (aside: Cole, you're a fount of information)
These conversation happen in-game. One happened to me, one other I found:
Cole: Can I help you? You healed my hurt, but yours is old inside, vast across the veil.
Solas: I'm fine thank you, there are others who need your help more urgently.
---
Cole: She is bare-face, embarrassed, and she doesn’t know. She thinks it is because of her.
Solas: You cannot heal this, Cole. Please, let it go.
Inquisitor: Perhaps Cole can get a better answer from you than I did.
Cole: He hurts, an old pain from before, when everything sang the same. You’re real, and it means everyone could be real. It changes everything but it can’t. They sleep, masked in a mirror, hiding, hurting, and to wake them…(Gasps) Where did it go?
Solas: I apologize, Cole. That is not a pain you can heal.
I think that Fen'Harel found a solution to the war and his solution had terrible consequences. I think that he sent the rest of the pantheon to some other dimension (as Morrigan suggests it's possible) and the Golden City became empty. I also think that it's possible that the real world was not as immutable then as it is now (shown by the Rift Mage specialization and what "Solas" can do).
I think that it was possible to freely interact with the Fade and when "Solas" says to imagine a world where spirits walked among us freely, it's not just wishful thinking, it's something that once was but got destroyed.
I think the Fade and the real world were one and when causing the rift to stop the war the two were made separate... "an old pain from before, when everything sang the same".
However I don't think Fen'Harel was or is evil. From everything he stands for in-game, to the fact that he wants to fix his mistake. And I watched and re-watched the epilogue and I just can't see that... him looking angrily at Flemeth. (What's more, if he were happy that she died, he'd have just dumped the body instead of holding it tightly and lowering her gently.)
He feels that he needs to bring back the people trapped on the other side of an Eluvian (or more)... the people behind the mirrors. His People. Because - to put it crudely - he f**ked up big time.
And since the orb is destroyed he needs the added power of Mythal to do it.