and he has done brilliantly. 
.
We did loads and loads of prep stuff, including walking the school run route for the last couple of days, social stories, visual prompts etc.
He hasn't slept much for a few days and has picked at his face a wee bit, but nothing too hideous. So I was only a bit worried. But he arrived, saw his friends from pre-school, started playing and that was him! He refused to make eye contact or speak to the adults until one of them enthused about his dinosaur shoes about an hour in - then apparently did great talking for the rest of the session.
My only wibble was that they haven't put up a visual time table or first/ then board yet - he uses those independently ish at home (we talk about what is going to happen, he sets up the board and refers to it constantly.) I think they need to get that sorted ASAP!
But a good first day. Now, just the next 14 years to worry about.