I consider a romance between Leliana and a Warden who survived DA:O as a fable about the problems of having different careers and keeping a relationship.
After DA:O:
Warden: "Sorry, Leliana, I know I promised that we would go on an adventure, but there's a darkspawn army causing problems in Amaranthine and they need my help".
Leliana: "Now that you mention that, my friend Dorothea sent me a letter. She needs my help too, and I owe her a lot".
Warden: "Well, I guess waiting for a year or two won't hurt, right?"
After DA2:
Warden: "I have discovered some clues I need to follow. I will be away from Ferelden for a while. What will you do?"
Leliana: "Sigh, Dorothea needs me for something called 'Project INQ'. I won't be able to accompany you".
Warden: "Don't worry, I'll try to write as often as I can. It's time I leave some codex entries of my own!"
After DA:I:
Warden: "Leliana! You won't believe what I found in...! Wait, how come you're the Divine?!"
Leliana: "Things happened".