is it possible to build a Group that has a Width and Height (with Binding) and is not resizing when the inner Nodes changed location?
Best if it prevents the Nodes from being moved outside the group too.

Any Idea?

For the first requirement, don’t use a GroupPanel. As an example, the Planogram sample doesn’t use a GroupPanel.

For the second requirement, you can override DraggingTool.ComputeMove to limit the Node.Location in any manner and under any conditions that you like. (It’s responsible for the standard grid-snapping behavior.) However it might be possible, depending on your app, to just set or bind the Node.MinLocation and Node.MaxLocation on each Node, since that’s another constraint that the standard implementation of ComputeMove heeds.

Thank you Walter,
the Planogram example is exact what I search for.