Mutli Room Baby Monitor - 2 cameras for 2 seperate room

For months now I have been searching for a reliable video baby monitor which supports 2 cameras for 2 separate rooms but will supply a video feed to one viewing device.

I have a son who is 20 months and a daughter who is 9 months old. Having 2 separate baby monitor systems is starting to become very annoying I would appreciate any recommendations at all which could help in this scenario as I understand some monitors can have more than one camera paired but you are not automatically notified between both cameras, it only gives the option to manually change from one camera to the other. During night time sleeps this is clearly not helpful as it would be great to be notified depending on which child has woken up.