Wait, I don't remember my Warden disappearing? Maybe it's been so long I just don't remember, but wasn't there an outcome in Origins where a female Warden could be Queen alongside Alistair? And Zev and I walked off together into the sunset, so to speak, at the end of DA:O, and the epilogue after Awakenings had him assassinating some noblewoman for me that was causing me trouble...and in DA2 if the scene had actually imported correctly (which is didn't) he is supposed to respond to Isabella's flirting by saying his current lover (my Warden) is a dangerous woman.
Enough of you are saying it, that I'm sure it's true...I did block out most of DA2 as a traumatic experience, so maybe it gets mentioned somewhere in there and I just don't know it?
It's mentioned in the final moments of DA2, when Leliana and Cassandra are talking to each other. The Warden and Hawke "disappeared" at some point before 9:40. There is no official mention of the Warden anywhere(unless Zevran or Alistair mention him/her) after Witch Hunt, the Warden just disappears. If the Warden romanced Alistair, and Alistair is king, it's doubtful they stayed together. Same if the Warden romanced Leliana, as she indicates no knowledge of where the Warden is. Zevran theoretically could have "disappeared" with the Warden(like every Hawke LI, save for Sebastian) but it's unknown.
The only romance of the Warden's that is likely to be "happy", in my mind, is Morrigan. Because, again, there's no mention of him by anyone after 9:33(when he could go through the Eluvian with her).