Before covering the windows we decide to verify our floor layout. A few hours later (and 2 rolls of masking tape lighter!) it turns out our layout is realistic. I'm expecting a few gotchas but we're at least within the realm of reality!

Next step is to cut & paint the plywood rectangles that will cover the existing window openings. (Unfortunately the plywood warped a bit because we stored it on edge for a few weeks. Store your plywood flat!) We'll weatherproof the windows by applying butyl caulk around the perimeter and a piece of flashing along the bottom edge.

The plywood is held in place with shims of scrap plywood wedged along the lower and upper frame

3 windows finished.

Another view.