I think you can get away with any length kurti tbh. The standard above the knee ones will always be in style, back in Pakistan though I've seen a lot of people sporting long kurtis (almost mid calf) over skinny jeans. They look reallyyyy cute too!!
Long kurtis are in with churidaar's or skinny jeans here in Pakistan. Although the usual ones are just as in. Its your choice what you decide to wear :=)