I watched the series again recently, so that's why it's so fresh in my mind. Probably my favorite show of all time. Or at least close to it.
She's also not that pretty. I mean, I'd still do her if that was a possible scenario, but she's not all that.
Also, in all seriousness, we don't need a TLoK movie or even an extra episode. Let's assume that those extra 6 minute rumors I brought up a lot (a lot) earlier are true, Day of the Colossus had 2 extra minutes over the one that aired. If The Last Stand got 4 extra minutes, that's plenty to cover any real loose ends.
What real loose ends are there? Let's think about that. All I'd want is a nice conversation between Bolin and Korra, just like she had with Mako, Tenzin, and Wu. I'd want to see a bit of reconciliation between Kuvira, Su, and Bataar Jr. Maybe throw in an extra bit with Mako doing...something. That's really it. Unless you want Jinora and Kai resolution, but by the end, no one cared anyways.
A movie/OVA/extra episode would be too much, and far too out of place. I'd really rather just have those extra minutes, a Director's Cut, if that's even a possible thing. Even the things I listed as loose ends are not really loose ends. Just nice little extras, but we definitely don't need it.