So far this seems to be working great. Ds8 has Taekwondo three times a week, tennis twice a week, dance twice a week, and piano once a week. Dd4 is in a great Montessori VPK program for three hours daily, and has ballet twice a week and piano once a week. With a schedule like that, it took us a little while to figure out what days would be better for what. Having shorter days on Tuesdays and Thursdays took care of that, and dh picking up dd on Mondays and Wednesdays helps me to concentrate school on those two days. On Fridays we review, catch up, and do projects. Every day the focus is on reading, writing, and math. The other two subjects sandwiched in between are ds' favorites - History and Natural Science. These are the inspirational subjects Charlotte Mason spoke about. Ds also enjoys Picture Study, Composer Study, and Poetry.
We've already been to a NOT Back to School Party, and are enjoying the ample opportunities to socialize after several weeks of Summer's self-imposed hibernation.