I believe I've been over-thinking this. (Me? Shocking, I know!) I've been trying to figure out what the best situation is in general, for all the kids, when all I really need to worry about is what's best for DD7 when she gets there.
I think she would be fine either way. She's pretty good with organization and remembering things. And if she needs acceleration at that point, the school is good about making it happen regardless of which building one is in.
It's fascinating to see all of your different models, though!
