If your going to need overnight accounts you will need to use either preorder or accounts, accounts is the property of doing it and preorder is a ‘hack’ which I wouldnt recommend.
If using accounts you will need an entity/account per bed if payment/account is to be per bed/person which would be how bookings would work however with the way my booking entity worked you would still need an entity per bed to select the guest. Alternativly given your situation you could maybe opt to use customer/guest entity/account rather than booking if you prefer.
Have a read of this topic, there was many discussions about options.
When saying entity per bed I am guessing we are talking hostel type and a bed entity would not necerserally have to refer to a specific bead but it would be one per bed ie entities;
Room 1a
Room 1b
Room 1c
Room 1d
Room 2a
Room 2b
etc… to give you ‘slots’ to put people in.
If I did this I would make a custom entity screen and group entity buttons in to blocks of beds in a room grouping arrangement.