Depends on the living conditions you insist on to a great degree. Do children each need their own room? Will they all share while small? Will there be a shared boys room and a shared girls room? How many children will there be? What limits on activities will there be? Public school, home school, private school? Eat out a lot or grow your own food in the garden? What about vacations? What is the actual numerical income of the household (a doctor or lawyer would has a lot more to work with than a fast food manager)? etc.
I think there would be significant "sacrifices" a family would have to make to intentionally be a single income family, but I also think there are some hybrid options (like mom goes back to work part time once kids are in school which greatly shortens the amount of time the household is strictly limited to just one income).
And since I'm unlikely to ever have children of my own, that's about all the more I think about it.