Oh! I feel your pain. We did that Thursday nights here in Sept. Oct. and Nov. I left work at 4:00 and didn't spend more than 5 min. at home until 9 pm (two soccer practices and a Tae kwon do class. My only advice is make sure the girls are prepared. Have them help figure out snacks, books, game boys, stuff that will help and prepare for your car to become the kitchen and dining room. Subway is your friend (because you can get half way decent fast food there) and protein bars by the case are essential (as well as gatorade and water). You might get one of those cooler that you can plug into the lighter on your car.

Good luck and I think you should stick with the Tae Kwon Do. You seem to enjoy it.