Discuss options with your son’s guidance counselor. In your case I would advise you, not just your son, discuss colleges that would be appropriate for your son given his abilities. At some point he will need to be able to keep up with the work. This means figuring out if he is able to get the job done in a timely manner once he finishes college.
The rigor of his HS does not mean lower grades are more acceptable to colleges. In some states the public schools can be much better than private, college prep schools- even in small towns. Students are expected to do well in their school. In college he will also face tests and needs to do well even with any accommodations. His GC should be able to have suggestions. The community college route sounds the most viable at this point. Perhaps his school (or the local CC) can offer testing for interest and aptitude to give other options as well.
It would be nice for you to know if his grades reflect poor test results but that he does well on assignments.