Turning Cliche On Its Head (Sort Of)

So I recently finished reading the "His Dark Materials" series a few minutes ago and part of it sparked an idea in my head.  Well, two, one a minor fix to something in the RD cycle, but another, a completely new idea.  On a sidenote, I thought the Dark Materials trilogy was pretty good overall.  They aren't as captivating as some OTHER popular YA materials (You know what one I'm talking about), but they have a million more times substance to them.

Anyways, the thing that got me going was the inevitable love plot between Lyra and Will.  Sure, Pullman set up an extremely sad situation, but I had no connection with the characters whatsoever.  I probably would've had a major bawwwfest if I cared about them, and the image of two people sitting on the same benches in different worlds, separated by the infinity of universes inbetween, hoping to simply recapture a moment in time with one another, it's touching, moving, and truly, truly stirring.

But the love plot itself; meh.  A lot of stories do this, where during the stress of being in war, or in hiding, or just against conflict in general, it brings people together in a relationship, and things typically end with a "happily ever after" ending.

I guess I want to turn that on its head.  The basic story idea I have is that two characters, once in love and brought together solely from some big world conflict or whatnot (really, take your pick.  We're at war and working together, or anything like that,  you HAVE to know what I'm talking about in literature) are now struggling to remain with each other because face it, after the conflict is resolved and the heat of the moment has cooled, none of those characters ever really have all that much in common.

My story would show the two main characters struggling to keep their relationship alive after the world conflict or whatever is resolved; so it seems like this big, major story is already skipped over, right?  Well, I want to tell their original love story through flashbacks and whatnot.  Maybe in the present they're arguing over something, and then it flashes back to how they met, and gives some details on what/who they're fighting against, on up to as their "love" grows and they finally defeat whatever evil threatens their world, to "happily ever after," to "well, what do we do now" (I think that's another great concept that is never really explored.  Just what the hell do you do with your life after tossing the ring in a volcano, killing emperor palpatine, sealing away magic forever,  or you get the picture.  yes, frodo sails away.  what's the emotion to that though?  how insignificant does everything AFTER that initial "we saved the world" high dissolves?), to "you're not the person I originally thought,"  to "maybe everything isn't so happily ever after," to whatever comes out of that.  Do they work past their differences?  Can they fix their relationship?  Or do they split?  Who knows yet.

A bulk of worldbuilding would come from these flashbacks, not only showing how the two main characters fell in love but the current issues of the era, what things are worth fighting for, etc.  It's very important that these are ideas tied into a single book, because I don't think a duology would quite have the same effect.

I don't know.  It's another idea, one I probably won't be able to touch for years yet, but I think it has potential nonetheless.  Thoughts?

(apparently the film "Blue Valentine" does something similar to this but I haven't seen the concept in literature, and that film implements its ideas differently.)