I don’t exactly know how it will go but a curious thing about my son is he isn’t terribly affected by big changes. It’s the little changes he can’t deal with.
For example when he went to daycare after two years of having a nanny they always say to expect crying and sleep disturbances and all that, even in neurotypical kids. But he never missed a beat. Likewise when he started school and intensive therapy. No crying, no crankiness, nothing. Happiest kid ever.
But if you dare switch up the nighttime routine, woe betide you. We’re about to take his big heavy blanket into the closet for the summer and we are spending an entire week preparing for that change. But in general as long as you give him advance notice, he’s pretty good.