I have BtS but I ended up deleting all the scenarios to save space on my hard drive. Now I want to play AoI but would prefer not go through the hassle of reinstalling civilization (and the patches). Is it available for download anywhere?

I have BtS but I ended up deleting all the scenarios to save space on my hard drive. Now I want to play AoI but would prefer not go through the hassle of reinstalling civilization (and the patches). Is it available for download anywhere?

Nope, you would have to reinstall and repatch.