Fair enough, in that case, none of the ones I just mentioned really count.
However, I can guess that when/if No Need for Destiny gets continued that Nabiki will pick up the Ice Queen persona again in her time in Nerima. I mean, Ranma starts talking like a jock again. It'd take a couple more chapters to see though.
When No One Else Would really can't qualify either, at least where it left off. It really doesn't get going much beyond what feels like the beginning of the story, so Nabiki doesn't really get the chance to fully develop. It had potential to do what you wanted to, but if it doesn't get picked up again, it certainly doesn't qualify yet.
I did think of one where what you are looking for is implied, except that the boundary of Ice Queen/non-Ice Queen is more based on who is around Nabiki. Am I Smart? by Penguin-sa changes the Ranko incident (where she thinks she's a girl) to having her imprint like Nabiki. Ranma and Nabs become best friends, and it implies that in the presence of others, Nabiki will maintain the Ice Queen, but outside of Nerima or just with Ranma and maybe Kasumi she will drop it. It's a pretty well written Ranma-chan, if you happen to like that genre, but most of the Ice Queen Nabiki stuff is implied.



