He is in remission right now, so it was a much better time to do testing. I hope that when he turns 6 in April he will still be feeling well enough to go through the IQ testing. If not, we will put it off. Although it is a catch 22 because the more challenged he is, the more his mind is off his pain.
Given the constraints you are working under, would the school be willing to do an IQ test, such as a WISC IV, now while he is feeling well. At the very least it will eat up some of that Kindy class time. I would strongly encourage you to push the school to decide about the skip now, so that everything is in place by April, so that he can move up as soon as is legally possible. If a school was trying to hurry things along, they would have to work hard to be ready by April.
Some may say, why bother to move in April, when the end of the year is so close to over? I would say the 8 weeks of a child's life is a long time. Also, if he starts 1st grade in April, then you will have the whole summer to plan the additional accomidation - more full skips or subject accelerations. Every step brings you closer to getting him what he needs.
It's ok that the school 'recommends against' for social reasons, as long as they are willing to do it if you insist. It's tricky to 'insist' when no parent feels 'sure' on the inside, but the actual research says that the social issues isn't the norm.
I'm sorry to hear that your son has such severe medical problems. I'm sending strenght and prayers to you.
Grinity