Charitable donations never save more in taxes than the actual value of the donation.
Say you're in the highest tax bracket, which is 37%. If you donate $100,000 to UPenn, your taxable income decreases by $100,000, so there's $37,000 in taxes that you're not paying. However, you're now out $100,000, so you still have $63,000 less than you would have had if you'd never donated at all.
Of course, his grandkids probably won't have a hard time getting admitted, but that doesn't change the direct finances of the matter.