As I said I lived in a flat, not sure where you got that from, landlord obviously failed to tell me about the magic "downstairs" ToTheRegimentIWishIWasThere
but I have never switched off the heating at night with young children*
It was behind that door, did you never look?! The back room amplifies sound into upstairs at ours, front room would probably be less bad on one side, but still bad for the other. We can't afford to have the heating on all night. It's alright upstairs because it's carpeted and next door usually has their heating on 
I was the only one in the building with children (small or not), the others could have made my life a lot harder than my babies could have, I am forever grateful the neighbours were lovely.
It's shit that you were at the behest of people who could have made your life difficult about something you couldn't have controlled.
I do get what you're saying about doing as much as possible to stop neighbours being affected by baby noise (and most people would want to keep neighbourly relations positive) but this particular author sounds like a proper bellend, I reckon his neighbours might not have been arsed that he was being woken up 