Do I think your child has a chance? Absolutely!
Yes, we used the Explore results + portfolio option for our son. I did have him take a WiscIV after I sent our application (for back-up) but they accepted him without my having to submit the IQ results.
My guy took the Explore privately through Belin Blank, where they sent the test booklet to a proctor of my choice (our homeschool charter teacher). I chose the February test date so if you like you can wait till then, when your child will actually already be in 3rd grade. I've heard that you can also choose to have your child tested earlier if you are using Belin Blank. However, since your child is younger, they may request for some kind of further info before sending you the packet. I sent them my son's results from another above-grade-level test and they sent almost immediate acknowledgement that they were willing to have him take the Explore.
