In my case I had over 50mb free before I tried to update. I had installed packages only from official repos but I still could not update OTA and it asked me to update via PC. I decided update using apt-get, but rootfs filled up. Eventually I managed to perform the update, but in my opinion rootfs space is insufficient.

It is true that average user wont use apt-get. BUT, before update I did only thinks which average user would do: install programs from official repositories and I could not update using package manager. So definitely everything didnt work as they should have. It is possible that some (normal) user cannot even do the update because of these issues.