To answer and to Ally G. When we would get orders we would plan out how far about three weeks in advance of the move to tell the kids. I made the mistake once of telling our son when we were moving very early and the whole neighborhood couldn't wait until we moved to have he stop talking about he move.
Time in a child's mind is different than an adult. Be positive and if you can visit before the move, do it so that he has an idea of what the new place looks like. Three years old is a very easy move it's when they are in middle school or high school that is different.
Enjoy the holiday and the new school.
the other S.
PS Be prepared for a month of wanting to possibly go back to the other school. He will be ok. Just go with the flow and don't make a big deal of it.