how to get the actual render screen back ?

I render to pgn files then in a second pass i render to movies
But now i have closed the video render screen, to checkout something in the model
Altough it is still rendering about 5 minutes of movie, I have no idea of where it is now,

Is it possible to open the render output screen again after one closes it, to see how the rendering is going, where i am, and how long the last render frame took ?

If I understand your question, open the Image editor and from the pulldown menu choose “Render Result”.