Could you plan for and approach an end of year skip instead of a mid-year skip? Maybe a skip in the middle seems hard, with disruption, not knowing the "rules" of the new class etc. But just making the jump with his math friends at the end of the year would be easier?
My son did a Christmas break skip from 1st to 2nd last year. His biggest concern was that he would get in trouble for sitting at a different table at lunch. It took a while to get to the root of what his concern was because he had been asking for months for the skip. We reassured him that the principal would take care of everything. Sure enough, the principal forgot to notify the lunchroom monitors and DS got in trouble for being in the wrong seat.
Sometimes it's the little things that get in their head and cause panic. If you can figure it out and smooth the path, it might be much easier.
