I have been transported back reading your post OP, your situation is so similar to ours. I have named changed to share my story incase it helps you going forward.
At the end of year 2, the wheels well and truly came off. What we would not know for almost a year from that point was that he had masked his undiagnosed ASD from everyone and almost equally shocking was an IQ of 160. But by then the ‘he is just a naughty child’ strategies of isolation and exclusion by school had compounded his anxiety and his inability to deal with teasing and peer rejection meant that he could no longer cope in a mainstream class. I was unable to work for most of his year 3 whilst all the assessments, exclusions, part time timetable, EHCP development etc was undertaken. I eventually had to resign my post.
I used the time to look at alternative schools, including independent, independent specialist and mainstream/ LA special schools and realised that there was nothing within a 90 mile radius that could or would be willing to, meet his needs. Moving was, and still is, not an option both financially and personally and boarding at 7/8 was simply out of the question. Trying to home educate him myself, whilst still on roll on a part time timetable quickly made me realise this was not a long term solution, as even though I am an experienced teacher myself, I was his mum not his teacher. Bringing in a tutor was also ruled out as he wanted to be ‘part of a school community’ as, regardless of his ASD, he remains a socially driven child. An Ed Psy, experienced in gifted education, explained that he needed to learn in a group situation and to bounce off ideas and thoughts with similar children or adults.
Once it became clear that the LA was only going to offer us the default of EOTAS (and well done for not letting him be removed from the school roll), We chose to fight for online school funding and a personal budget to cover the cost of things that he should have received at school (eg swimming /various sports lessons) and EHCP requirements such as social communication support (we use this to fund buying the Michelle Garcia social thinking system which was recommended to us given his profile) and costs to attend things run by a local ASD charity such as a weekly social group and lego therapy, etc.
Fast forward to now, and at almost 10 he is still at home, however, he is very much a part of his online live school community. He does live lessons each morning, he is in a class group two years ahead for most subjects. He has ‘online class friends’ and in the afternoon/evenings he is able to join in some local activities. He recently joined a local chess club with his dad and really enjoys playing with the older children and adults.
I went back to work (teaching) two days a week in November on a long term supply contract. He goes to his grandfathers (with his laptop) for one day and one day I use his personal budget/DLA to fund an ASD experienced TA to support/redirect him during his morning on line lessons and then in the afternoon she does some thrive/social communication work with him. Working has given me back my emotional stability and enables me to support him the other days. Yes we have less money, a very old car and no fancy holidays any more, but with his personal budget, DLA and me working a couple of days a week, we have been able to stay in our home and close to our family support network.
What supporting him in his online lessons made us quickly realise was how our boy who could articulate exceptional well with adults, was not able to communicate effectively directly with his peers. It really helped us to focus his support on his social communication needs that neither we or the Salt during his EHCP assessment, had not picked up on. No wonder he struggled at school and communicated his distress in action and not words.
We will shortly start the process of fighting for an independent specialist placement at secondary level. Mainstream secondary will not be an option where we live. We know there are only two or three suitable in the U.K. that can meet both his ASD and educational needs and that this will mean boarding. However, that will also brings social benefits for him that will help him longer term. What I do know is that being at home full time for these past 20 months reduced his anxiety significantly and gave us the opportunity to do a lot of social communication skills learning and self regulation development with him. He is no longer the sad, anxious, angry child he once was.
If you feel that only a physical school is appropriate and you cannot travel to the Independent specialist school in the next county, then you will need to fight the LA for full time (including breaks, etc) targeted 1:1 support, not just a banding amount. Expand your mainstream search to include larger schools that may be better equipped than most smaller schools and I would play down his academic needs, as that will probably scare most schools, almost as much as his ASD and to be honest his social and communication needs are probably more important at his age. But you will need to understand that the social and emotional needs are likely to increase and most MS are ill equipped to deal with this. Alternatively if you feel it is the most appropriate place, go back to the ASD school that rejected him and ask them what additional and specific support would be needed to be put into place for him to attend. If this is a LA maintained ASD school, then fight the LA for that additional resource.