Question: How to drag windows to another workspace from the "Spread view"?

EDIT: Seems to have created some misunderstandings by using the term "Spread View". I am referring to SUPER + W " Spread windows view" and not to SUPER + S "Spread worksheet view" aka "Workspace Switcher".

Answer: 
From the *spread view* (`SUPER` + `S`) just grab the window and drop it on another workspace.

P.S.: It seems as though there was a slight misunderstanding with what you regarded as the *spread view*. You can always hold down `SUPER` to see all Unity shortcuts and their effects in a nifty overview.
I don't know exactly what you mean by the "spread view". But if I have a window that is in focus, and I want to put it on another workspace, I usually do `Ctrl``Alt``Shift``Right` (or Left).