It is easy, in that you can just unplug them from power and store them until next use.
 

In this situation, it may then take a few minutes for your Beam to re-acquire them… and you will get the app telling you it’s lost the speakers and it keeps trying to find them. To avoid this you could “remove surrounds” in the app before unplugging, and then re-add them when next used. That should only take a few minutes, but there may also be times when your Beam gets updates when the surrounds are not in use. This means that after reconnecting them, the surrounds will need to be updated before they can be used. 
 

So yes, it can be done easily, but is not really very practical. 

Thanks nik9669a, I understand what you say about the practicality of doing this  but I can put up with the inconvenience of running an update if required as it doesn’t take that long based on my experience so far with the Beam. It would be great if I could leave them in the room but as I said for various reasons I wont go into,  I cannot do that.

Be aware too that all of your Sonos devices will mute during update, so it may be best to turn off auto-update and then manually select when to do updates.