adamantly refusing even to shadow
Taking kiddo there on a stealth mission a week or more before the shadow date, just to watch the kids arrive in the morning or be dismissed at the end of the day... may help him get a feel for the environment and also help prepare him mentally as he could then picture the school, the door to go in, etc. While scoping it out or "spying" you and your child could discuss that the kids seem happy, seem friendly and visiting with each other, that the noise they are making seems joyful, whether the kids seem to have backpacks, or anything else he observes that might help shadowing seem a bit familiar and encourage him that he'd be accepted and fit in.
I hesitated to post my recommendation because it goes against most of the other opinions on this thread. I agree with indigo that you should sneakily get him to the other school and observe that school on some pretense or other - maybe go to their Winter music recital program or a sports event there etc.
Why I say this is because my child had a horrible K year - but adamantly refused to visit, shadow or think about another school. His K friends had become his lifeline - his life revolved around recess play with some, looking forward to a superhero themed birthday party for another, field trip coming soon etc etc. He could not think of a life beyond his current friends and how he would miss out on all the fun if he left. So, not wanting to cause emotional trauma or feelings of abandonment etc, I waited out the K year in his current school while spending a lot of effort to after school to make up for the lack of challenge.
I put him in the new school for 1st grade with a lot of peptalk on how he was going to learn great new things with the Principal meeting with him for 20 minutes and the teacher taking him on a classroom tour etc. And then, here is the kicker, he loved his new school so much that he asked me in the first week why I had not overridden his objections and brought him there during K. He has made a ton of new friends easily while he had problems making friends in the old school.
So, that is my way of telling you to get your son to the new school and he might surprise you by changing his mind. You can tell him that there will be no changes and that you are visiting to check the school out just to get an idea about that place.
Good luck.
