I would mount one long curtain rod and use four panels. Use something like grommet curtains or clips and metal rod so they are easy to slide back and forth depending on which windows you need blocked at any given time.

We got Miulee velvet blackout curtains, to the floor, for our sliders and windows. french doors, and are always adjusting them for the sun depending on the time of day... or for the TV, etc and it is so convenient. They fold flat between the windows when open.

tracefloyd, thank you! We have silhouette blinds on all 3 windows so the curtains would be used only for staging the windows with decorative panels. The fabric is a light cream color with a subtle vertical design. Would you still use 4 panels…or 2?