Ok, so Diana is moving out on November 30th, a week from now. I want Rudy to move in once my 10th slot frees up. If I find someone with Rudy in boxes, can I ask him to move in even though Diana hasn't left just yet? Will he move in once she's gone? Or do I have to wait until her house is gone to ask? I just really don't want any unwanted villagers snatching the slot once she moves.
It's my understanding that if you already have 10 villagers, you have to wait for her house to be gone before you can invite a new 10th villager into your town. If you are willing to time travel, you could find somebody with Rudy in boxes and then time travel to the day Diana is gone so you can invite him. If you don't time travel or can't find someone with Rudy before Diana leaves, I would suggest minimizing or cutting out any online play until you get Rudy to make sure you don't accidentally pick up someone's voided villager.