Hello Y.hartmann
Thank you for your question. Officially, we do not have m2 specifications for our devices. When the battery is empty, the Roomba s9+ goes back to the station, charges and continues where it left off. Otherwise we would recommend you to ask iRobot directly for a test device. There is the possibility to test a device and afterwards you can still buy it on Galaxus.
Your iRobot Team

The area should not be a problem for the Roomba and with the app you can programme all times at different days of the week.