Buy back the "family farm," most of which was sold after my great-grandfather died
Rebuild the house on the portion we still own...termites have caused a lot of damage
Pay off all my brothers' debts
Set up college funds for our kids, my brothers' kids, and all the grandkids...for as far in the future as we can see
Inform my kids that they will have to go right on supporting themselves until I die...don't want no stinking liberals in my family.

Build an underground house, passive solar, wood heat, etc...the goal being to end up with a place that really has no utility bills. I'll buy several sections and put the house in the middle. No roads. Unannounced visitors will not just stroll up to the door.

Invest half the rest, carefully. Give away the other half.