Dual Enrollment is being coenrolled in high school and community college or university at the same time and can often get you a full year’s worth of credit and AP weighting for one semester if you pick your classes precisely based on the state you are in. CLEP is testing out of a college course. Just because are not offered at your school does necessarily mean that you cannot take them. The purpose of going down to regular or taking online course (i.e. flvs.net) is that you can take something else rather than spending your time on something you will not use. Taking dual enrollment courses is a complicated process, and you would have to ask around at local colleges. The reality is that it depends heavily, but at the very least you can find courses online that are fully on the web. It can vary from thousands of dollars to a couple hundred, so pick wisely. You do not have necessarily even have to stick to one high school either if you can transport yourself midday.
You get released early or get a late start by taking eschool or dual enrollment classes. If you want a lax period, take a class online and study at home. You do not even have to attend high school full time if you can come up with something like a porfolio. There are always loopholes that get you out of the jurisdiction of the district if necessary. It is your life. Take control of what you can and show some initiative. The road most traveled is not always the right one.