Since it hasn't come up for me I haven't gotten an authoritative opinion on the matter.
But the IRS rule as I've read it is that I could deduct up to half of adjusted gross income
for qualified charitable donations.
So taking cash value of $250,000,000 which should be also adjusted gross income,
you can give 1/2 of that and deduct it.
Essentially the result is I'd be giving about 35% to charity instead of 35% to the government as
federal income tax.
You may deduct a maximum of up to 50% of your adjusted gross income (AGI) (Line 36 on IRS Form 1040) for the tax year the donation was given. However, if you give more than 50%, the excess may be carried forward for up to five years. Be aware that the 50% rule applies to most contributions.