Well this is a great problem to have!
So you don't need this money in your lifetime? Should I send you my address, or is wire transfer good for you... :)
What do you want to do with this money? Pass it on to heirs or donate it? I'm no expert on inheritances. I received a small one that was in a pre-tax account and I had to pay income taxes on it when it was cashed out. If your heirs will be in a lower tax bracket than yourself, it would mean lower taxes on that money. I don't think this solves the RMD problem.
Any part of the pre-tax money you donate to a valid charitable foundation should be a tax-free event for you, since you won't benefit from the money. Why would you set up your own charitable foundation? Sounds like a lot of work, and ethically you shouldn't be looking to enrich yourself via such work. I think this is what jmwagner was put-off by. Financially I think you should consider donating the money the same as paying 100% tax on the money. The difference is you can direct what charity the money goes to vs. into the federal government.
One path is to start taking distributions before 70 so you can smooth out the taxes, assuming you'll be in the high tax bracket for life. But on the other hand, at 250k, you're already likely in the 33% bracket (231k-413k), depending on deductions and final AGI. That bracket is quite large, so your RMDs aren't likely to cost you more in taxes. Even if they did, the next bracket is only 35%, so it's not a huge jump.
As soon as I was eligible for penalty free withdrawals, I would start withdrawing enough to fill the entire 28% bracket (until AGI reaches 231k). Of course the brackets change over time and tax law can change. Once you hit the 33% bracket, I would not withdraw anymore - let that money continue to grow tax free. Eventually you'll hit RMD and you'll just have to pay 33% on those withdrawals at that time.
One more question - what happens if you die? Does the 250k stop? What will your wife live on? If 250k goes away, it would be nice to have more of that 401k available pre-tax, as she could draw on it and pay much lower taxes.