I was curious if it was possible to detach a "Sub-window" into its own stand alone window, that way i can have one monitor dedicated to my work-space, and another dedicated to the Full view of the image?

No, that's not possible, but you can show the same image in multiple main windows. See the Window menu.

If its not possible by how i was thinking of doing it, could i do it with another instance of krita?

Just open another window, and in that window open another view on your image. Note: you need Krita 2.9 or higher for that.