No it is not easy in a non accessible room.
turning the scooter around in a very tight space is quite difficult.
trying to hold the door open and backing out is equally difficult.
leaving the scooter in the hallway overnight is not an option.
if you are near one of the elevator vestibule’s, you may find a little niche where you can park the scooter overnight.
One other thing to be aware of is that the scooters use US pugs. If you park the scooter in one of the corners festivals, there will only be European plugs there, so you must bring an adapter.