Hi Artsmartmom,
Well, you already have learned that moving to try to find the best school doesn't always work out. So if you do it again, I'd recommend doing many things to figure out if the school would be a good fit (or move to an area with several different choices in schools for HG kids, in case one doesn't work out). And first, are you sure the school wouldn't accept the testing you already have (I'm guessing from what you've said that your DD has a qualifying score on the WISC?)
Can you see if you can get a list of parents who are willing to talk with you about their kids' experiences at the school? And make sure when you talk to the kids, explain what your DD's personality is like, because I think that makes a big difference in whether a particular HG+ school will work out for particular kids. Eg., there is a great out of the box school in the Twin Cities area that allows kids to work independently at their own pace, alongside other kids at their level without regard to grade level. This works great for a highly self-motivated kid, but at this point probably wouldn't work for my kid, who isn't particularly motivated at this point.
I would ask the school very specific information about what they do for differentiation. PG kids can be at widely different levels in different subjects.
Also, I'd ask what many of the kids do after 5th grade. You never know, maybe there's a movement to add grades to the school. It sounds like a great program, but get ready to do a lot of research before making a move!
good luck.