Many wise posts above!
I think bullying happens less in high school than middle school. Maybe others agree, maybe not, but that has been our experience.
Does he have a 504 plan?
I have a kid whose medical issues prevented going away from home during elementary, middle and most of high school (including sleepovers, and social life was impacted severely for many years). When it became apparent that she could, indeed, go to college, she went to a summer program in her area of interest, the summer before junior year. Perhaps the worry about spending a night away from home could be delayed for a year or two.
It sounds like helping him find “his people” in high school, whether in school or out, is really important. Interesting that people mentioned theater, band, chess and robotics. Those are all areas where many of us have seen kids on the spectrum thrive. High schoolers need a “home” within the school, whatever it is, and “tribe” of peers.
I wonder if a program like “National Outdoor Leadership School” would help. You can google it. Wilderness expeditions like that would certainly mean he would sleep while away!
A lot can happen in the next few years. And there are many ways to do college. Adult learner programs (which allow part-time and are not residential), extension and continuing ed programs, online programs, distance/residency programs (attend weekends, or attend 10 days per semester) and so on. There are also schools like like Lesley that have programs (Threshold?), Curry, New England College and of course Landmark is a great resource and has a program for transitioning, I believe.
I don’t know if there is a school relatively close but I know I ended up spending a lot of time on campus and even sleeping on floors when the medical stuff got bad. It can work out even with some challenges. It’s not like your support will drop off a cliff.
I think you are wise to start thinking about it but I also think it is possible you will worry less in a couple of years as he grows- as long as he matures and gets engaged in the world (without further bullying).