We are just an ordinary commuting family. We don't have a car yet. "Yet" because, once you have kids, a personal vehicle will be very helpful in transporting a family and so it is a priority for me.
When we commute, we have to bring our baby kit. It used to be the diaper bag but since our baby's almost 3, the handy diaper mat was a big help in keeping things organized and portable.
But with the milk, we used to place it in the dispenser, the 3 layer container with holes plastic thing, where you put your pre-measured milk, plus the bottles with the distilled milk in it. If we were going to the malls, and might stay for the whole day, we'd probably bring 2-3 bottles and that milk container. Of course you can imagine how'd that stack up in your baby bag.
But recently, I've started using plastic ice bags to store the milk.
Yes, it is not a 100% environment friendly solution but my back is killing me from bringing the bulk by commuting.
Take note of the stroller as well as part of the entourage.
Using the plastic milk dispenser, at the end of the day, it is empty and it is still occupying the same space. With this, the more milk you consume, the less you have on your bag. Plus with abundant bottle water in convenience stores, I don't have to bring the all the water for 3 servings. The water bottle is another environment issue altogether.
So as you stroll in the malls, and allocate your shopping items, it gets messy, bulky and heavy. The stuff in your baby bag gets less as the day pass and accomodate the other small shopping stuff.
It's not a solution I totally admire for environmental issues, but heck, it helps me with my strained back and eye problem.