One year ahead should not be unmanageable in the classroom, in fact most classroom would have a kid or two working a grade above the current level.
But it is worth a try to move to 2nd for reading/math and maybe staying in his home grade for other subjects?
**If I were you I would try the split grades and then reevaluate in a few weeks.** Base a skip in on how that goes and possible the IAS. The fact that they teachers are receptive is great- it means they want to work with your DS and make sure he is learning.
Does your state/country have Gifted funding/teachers? If so that may be a good option as well.
That said- a LOT factors into it. I would as them to do an Iowa Accleration Scale (IAS). That may give you a good idea on how your DS falls in the big picture. Then look at the area you are in: is it high red-shirted? Is your Ds old/young for grade? Are his writing skills above grade level (which can be tricky if writing is not at the level needed for 'moving' up grade) Is your Ds mature enough to do better in the next classroom up? What are the teachers like in the next grade up?
I can tell you our story:
DD are appropriate for grade in our state, but we moved from a state with another cut-off date and they were in PreK. They went from PreK to 1st. So they are young for grade currently in 2nd. They are the 2nd and 3rd youngest in the class but academically are at or above grade level across the board. Socially-- I would prefer they would have done K instead of 1st since they seem 'immature' but are actually at or around age level, but a year is a big leap. They are still 6 (turning 7 soon), some of their peers are already 8.
Academically- there are several other kids in their class that are above grade level as well. Writing/spelling is individualized, as is reading (done in groups). Math has some enrichment. So overall some kiddos that are a grade ahead have the ability to work at their level. Now if a kiddo was 3-4 years ahead, the school would have to find another solution.
If we move they will be *the* youngest (unless we move to a state with a Dec cut off) so I really am not terribly comfortable with it. One DD has other special needs so that makes it a unique situation, but still at times I wish we could have them in 1st with accommodations for 2/3/4th grade work! Haha...in a perfect world.
My sister went to 3rd grade when in 2nd for reading. She was also young for grade. It did not work socially and since she went to a thematic school the 3rd grade themes did not fit the other subjects she was learning in 2nd.