I agree with Cricket that asking for a one grade acceleration first may be a good idea. And there is a good chance that there will be other kids one grade up scoring the same on the MAP. If the school has little experience with acceleration, the best way to show success is through increments.
Another thing to consider is your child's handwriting. We found resistance in our local school when we asked for our kiddo to go up another grade for math because they said he couldn't keep up with the writing. We found a school that didn't focus on the negatives and said that if he could explain verbally that he understood the concepts, that was fine.
It is good that you have a good relationship with the teacher and principal. This is crucial. You do not want to put them on the defensive by sounding demanding or telling them they are not doing enough for your child. What has worked for us is asking advice based on the data we have.
As for waiting for the WISC results, note that most teachers have little interest or knowledge about IQ tests, and many times that info doesn't help a lot if you are just presenting numbers. What helps more if the tester can write up the results in a way that discusses what types of school situations will work the best for a kid with those types of scores. I recommend that you meet and discuss school options and ideas with your tester if possible.
The Davidson institute has some great materials on advocacy in their resources section. Good luck!
