so I have 8 villagers settled in my town. The 9th villager has her plot reserved. My friend has one of my dreamies in boxes. Can I go talk to my dreamie villager today or do I have to talk to him tomorrow when the 9th villager is unpacking?
If that villager has already plotted (assuming you're using an already created character or saved a new one) then you are free to adopt someone else. The villager who is already there will move in as planned and the one you adopt should move in either the day they're unpacking or the day after.