how about a "3-week schedule"? 2 weeks for a song 1 week for an anything video and after being done with the anything video use the remaining time of the week for a big project. I think it's an optimized schedule cause you can't break it since you have the original 2 weeks for the song and potentially have 1 week for the anything vid but if it takes less time you can make progress on another project.
that is a reasonable idea