This doesn't seem too fair to their spouses, who essentially are responsible for all weekday chores. Perhaps the commuters can do stuff like personal finances on the train... but that's basically it.
The money the other parent brings home they would still need to earn it if they were single parents.
You can solve this 1 of 2 ways. One is you outsource much of this; hire a maid, eat out every day, maybe someone to do your chores (what was that startup called?), hire a nanny, but once you do this are you really saving money by living outside of the city?
The second is just push all chores onto the weekend. But damn. During the weekend you only use your house for sleeping and on the weekend you only have time to catch up on chores. Pretty much 0 relaxation / fun time.