The other thing to remember is that $1,232,633 is fully taxable at ordinary income tax rates (usually fed and state) unless you get a chance to convert to a Roth somewhere along the line.

The sum is subject to manadatory distributions at age 70-1/2.

So unless you have a magical tax strategy to avoid those taxes, its spending value in retirement should probably be reduced by 30% or so. And then you can factor in inflation (most expenses will double at least twice in 30 years).