Bought and beat Trespasser in less than 4 hours last night! It was fun! I rushed through it and plan a perfect run when I have more time, but it was quite the eye-opener!
My Lavellan would probably plot to kill Gaspard from the shadows anyway. And Teagan is just...a big nope as well. xD
Varric would be fun if I were to go for something more lighthearted. They could still be the best of buds, just with a ring on their fingers for the political gains. It would help Kirkwall most likely, but I doubt that she would have a lot of influence over changing the lives of the elves for the better.
Alistair would be REALLY fun. Complicated, but fun. (Against my canon worldstate, but really freaking cool.) I could write about a lot of things and it would put her into a position where she could do good for the elves and search for Solas on a much larger scale. Sebastian would most likely push her even more into the role of the Herald of Andraste. Gosh I have no idea. 
This is actually an excellent plot idea, with Gaspard, you know. Lavellan agrees to marry Gaspard for political reasons. Then she conspires to kill him, thereby becoming Empress of Orlais upon his death. But Gaspard is wily so it wouldn't be easy...
I can see it now. Lavellan: "If Andraste did not bear any children, then neither will I!"
Andraste did have children. It's just that at first because of her apparently frail/weak form, she wasn't believed capable of bearing them and surviving. Don't remember how many of them were actually hers.
I would love a Dorian/Lavellan political marriage. Dorian may need someone for appearances (Even though she's an elf.. )and on Lavellan's end it could be for peace between nations? I don't know much about politics or how much political clout Dorian (or even the Inky) actually has, but he's the best buddy Vint!
And if Adoribull is a thing, they'd be cool with that..?
Do share! ^
I think this idea's been done before with Dorian/Lady Inquisitor. Considering political marriages for appearances are one thing he stands against, though, it just kind of doesn't fit him? You'd need a super good reason for him to do that, rather than refuse on the grounds that he's not into women and he's not going to pretend to be someone or something he isn't for the sake of politics.
Hmmm, if Lavellen is just a Free Marches Comtess, with no other ties, I can imagine the best political marriage ever - endless games of wicked grace, cheap booze in the Hanged Man, the occasional argument about who will pickup the kids from Daisy the babysitter, 100% not awkward.
If Lavellen's clan is power in Wycome, perhaps they'd want an heir - it'd be a shrewd politicalmove to capitalise on Lavellen's reputation, and might get complicated then. Although I'd hope after years of travelling the Dalish are probably not going to be too into nobility - I imagine they'd run the city through the council and make noble voices ineffective if they could, because they have a limited legal status and if they hadn't freed Wycome of red lytium, they'd lack a mandate to be in power.
June is the best pantheon elf, even in cat form 
Well, if Clan Lavellan wants an heir, they're going to probably want that heir to be elven. I can't think of any other high ranking elves, unless it's maybe someone from the College of Enchanters (pretty sure you don't want the Circle of Magi involved, especially if you are a mage).
On the other hand...
Dear Abelas,
I hope this missive finds you well.
It seems I have recently come into possession of landholdings and a noble title in the city of Kirkwall. Seeing as you are a leader among your people, and I am a leader among mine, it stands to reason that there would be much to gain politically and socially from a contractual agreement. Would it be too crass of me to raise the topic of a potential marriage between us, uniting my people with yours?
Your standing and mine are more or less equal at this juncture. Since the Inquisition has disbanded, my forces have become much smaller. Yours were never particularly massive. Should we unite in marriage, we would both gain in martial strength as well as political. Elves would stand to benefit--alas, perhaps not in the way that you would prefer, but a place would be made for your people without the usual scorn and dismissal that my people suffer, while my people could finally begin to live away from the shadow of that scorn.
This is a chance for both of us, and I do hope you will consider it with sincerity.
Mythal enansal,
Former Inquisitor Lavellan
(Abelas would probably burn that letter...)
.... LOL, can you imagine Inquisitor convincing Solas to abandon his plans to restore elvhen people by presenting him the frilliest of frilly cakes? 
Inquisitor: ".... How can you sacrifice such goodness!?" (holds a shiny, frilly cake in both hands and does puppy eyes)
solas: "You.... You convinced me! Damn the elves. Our cakes sucked anyway!"
It would mean so much more to him if the (romanced) Inquisitor were to leap out of the frilly cake.
Also, regarding a political marriage with Varric:
It's possible Varric might agree to it if he were feeling similar pressure to produce an heir. But, if Lavellan is the Keeper's First, you'd probably be expected to have little elven babies--which you won't get with a dwarf, although if the theories and hints about Sandal and his origin are true, you might end up with a dwarven mage. I'm pretty sure dwarf/anything hybrids are pretty rare in Thedas. Not very fertile if not with other dwarves, maybe? Whereas according to the Orlesians at least, elves breed very quickly within their own species.
Much as Varric will always prefer and love Bianca, though, and since he says he's only into dwarves, I just can't see him even trying to produce an heir unless it's a Cadash he's trying with. I guess he could claim he tried and it just didn't happen. He does enjoy spinning tales. It's pretty sad he's always going to be hung up on Bianca when he can't really truly be with her... but I suppose the same may end up being said of Lavellan in the end, too.