Could I Really Have Thought That?

My concept for this painting of my cat Bonnie lying on the carpet was that its main feature would be dramatic light.  There is a band of light coming from the window "off canvas" to the left that illuminates a strip of carpet and the front of little Bonnie.  The rest of the painting would be in deep shadow.

I carefully drew the cat and the pattern in the carpet where the band of light falls, but I thought that for the part of the carpet in very deep shadow there would be very little detail - so little detail, in fact, that I could just "wing it" with suggestions of color shapes.  Could I really have thought that?  Naivete?  Foolishness?  Hope?  At this point, "just winging" anything in the carpet seems pretty impossible, not just because of all the detail, but also because of the perspective in the pattern.

At this point, I'm pretty sure that I'll need to draw in the rest of the pattern.  But for now, I think I'll continue to work on the light strip and the first pass at the cat.