If you get Snow Days, try and send your child to school before 8am anyway. I nearly had a Snow Day destroy my Dynasty (it hit the same day the heir was due to get onto the Honor Roll); at 730am, I just manually told the children to go to school, so they hopped on their bikes and went.
The whole day was spent with "Snow Day!" instead of "Learning!" but at 3pm, I had Honor Roll.
So don't give up just because of that!
Edit: And this Snow Day hit on a Friday, with the children due to age up on Saturday.