Pretty happy with my mobile setup so far.

The laptop sits on a Roost, and will not fall over to the right without a significant push.
The iPad is clipped onto my Macbook with a Mountie. Connected via USB using Apple's sidecar feature. Since I carry an iPad anyway for reading and videos, not much weight and volume is added to my backpack (I do carry-on luggage only).
Now I just need something to put the the keyboard, mouse, roost, mounty and cable(s) in, so I don't forget one of them when going to a work space.