why is it poor planning? Just trying to make the most of your time in LoS but IO doesn’t see it that way (and you are still following the rules IMHO (leaving the country before your extension of stay is due))
6am next morning is next day as days run from 00:00 till 23:59
if you don’t want to overstay exit before 23:59 ON the day your extension is going to expire
As said one day overstay is not a major issue just don’t get caught on the way to the airport