Also worth noting that Negi (maybe at the behest of his editor) put that camping trip arc in there as a place to stop the first anime season. It would make a lot of sense to give a big hint about the bride in such a place, especially if you weren't sure at the time it would get another season.
Scrambled Eggs is positioned just right for big hint #2.
Either this series stops somewhere around 100-106 chapters, or that's where the last big hint will be (unless Negi really wants to go a shitload more chapters, but nothing shows that desire on his part).
I mean, I realized it was basically down to Ichika and Nino before I came to like Nino. Miku, while she was the first quint I considered my favorite, always struck me as the nice girl who gets some sweet scenes with the MC but doesn't really amount to much in the end. At that point, I basically thought Itsuki was the bride, but that left a whole bunch of questions open that only Nino really answers. The bracelet, why she was the first quint he gathered for the festival (and why he told her he'd get the others), sacrificing the charm to save her life and not having that be some other quint instead, why she now knows so much about Lolikano instead of any other quint, etc.