I should probably chime in here. I have a 7 y/o and a 4 y/o and we've spent the majority of our life parenting living car lite, and you are right, it takes commitment.
We've been carlite before that - when we first returned to the US from Central America we decided it was no longer worth the cost or hassle. We started our carlite journey in Denver, where the weather was more forgiving, but have lived for the past ~2 years in Minneapolis, MN and had to work with cold and harsh winters.
I'm a fairly passionate bicycle advocate so I make a lot of sacrifices to make it work. When we relocated two years ago, the walkability/bikeability/transit access of the house was one of our top priorities. As a result we have a small(er) home in Minneapolis but we live nearby our daughters' schools, excellent parks, an extensive trail network, and restaurants/grocery stores/drug stores/etc. Extremely bikeable, pretty walkable and right off the train/bus line.
We've also invested in cargo bikes that can dutifully haul children. I suspect they are less expensive than a used car, but we'll probably recoup much of the cost when we decide to sell them and frankly, it isn't about the money (though that is nice). My daughters have a unique perspective on the world - they see their community, which is a real gift. They are incredibly adventurous, outgoing, treat the community as an extension of their home - and play in it as such. We try our best to be "free range parents" (once known as just "parents") which I am hopeful contribute to these awesome little girls. As they've learned to ride their own bikes we've also spent a little more money than the average family on their bicycles. I wanted to ensure they could ride easily, and enjoyably, and weren't discouraged by the wrong bicycle.
The average workday goes something like this: My wife leaves early in the morning (in our van in the winter, on bicycle during warmer months) for work, I get the girls up and ready. When it is warm, they ride their own bikes with me to school/preschool. After dropping them off I continue on to work. When it is time to pick up my wife will either wheel over to get them or drive home and walk up to the schools. The van sees the most use during the weekends for a bimonthly trip to my brother's house in the suburbs (he lives about 40 minutes away), driving out to mountain bike trails around the city, camping/lake season here in MN, and for my wife to get places when it is too cold for her liking. (most of winter, some of fall/spring)
It isn't always easy, in fact sometimes it is downright hard....but I enjoy figuring out how to do it better each time and really appreciate how it has affected my daughters' view of their world.