You have to control the rooms individually. Controlling multiple rooms as a group has been requested for some time, but never seen any progress on this feature.
If I was developing the Tado app I would add ‘zones’ which have their own smart schedule. If you assign a ‘room’ to a ‘zone’ then the zone’s smart schedule takes precedence. Each room would continue to sense its own local temperature/humidity, but the user would select one room to display the values on the zone tile. For example, if I had a zone called ‘downstairs’ I would choose to display the temp/humidity in the ‘living room’ on the zone tile.
Each zone also has its own manual control configuration and manual control of a zone would affect all rooms in the zone.
I would retain the ‘home view’ to display the tiles for each room, but add a new ‘zone view’ on the ribbon menu to display tiles for each zone. For basic/novice users the operation of the app is unchanged, as they can ignore the new zone view.
You could do some of that with what's currently available? If, for example, you had two bedrooms facing south and two facing north, you could have new rooms called North and South and put the 2 lots of 2 into the appropriate new room.
I've been toying with scrapping the 4 bedrooms I have setup currently and just creating one room called Upstairs so I don't have to manage the schedules on each one individually. Before I do that though I want to know how various things would work.