I see what you're saying there, but perhaps look at it this way:

our comfortable retirement is dependent on a good crop of reasonably successful children being born now, or in the previous 5 years.

It benefits us that those children are brought up to be balanced, rational pragmatic people. Perhaps extended child care might be the thing that does it?

I suspect that five years is indeed too much.

However perhaps the answer is one year "off" plus cheap, good quality child care from 1 year plus?