Window split as well as pane split

I’d love to be able to, when dragging a tab to a border in order to split a pane, have the option of splitting a window instead. Bit hard to express, so I’ll give an example:

I habitually have a window that is horizontally split into two (top and bottom), and each of these panes has a few handy tabs that are more or less permanent residents. Sometimes I would like to be able to split to the side and have another pane that takes up the whole vertical of the screen. At the moment in one step I can only split the top or bottom panes.

To work around this I need to start with a vertically split pane, then horizontally split one side, then populate with tabs. The numerous tabs in spots I’m happy with make it a more tedious operation.

Is there any way to split the window rather than the pane?

I did see this thread, which talks about how the panes are draggable, which is great! but doesn’t quite allow for what I’m hoping to be able to do: