I grade skipped 3 to 5 in a group of about 8. Most elementary did this at that time in my jurisdiction. So you didn't need a huge IQ for that grade skip. Anyone on the higher end could have done 2nd to 5th. But you have to cover the material -- and this is the time going from printing to writing, maybe something insignificant to many but it is a skill needed for speed and communication. And I had the advantage of a peer group for social reasons. If you do the 2, the social disadvantages will be more concerning.
