Temporary pleated paper shades that come with little clothespins to gather them up at the bottom and clip them open?

If there's easy access to the outside of the window could you rig up a cheap bamboo shade outside the window and just raise it in the morning and lower it in the evening? (Don't ask me how!)

Have used the temporary shade. You can get them at HD or Lowes. They have double faced tape at the top to stick to the inside top of window frame and are pretty inexpensive. I don't know if they come big enough for the large window, but if not you could use two.

Use a tension shower rod on the large window. You can buy inexpensive pole top curtains ranging from light filtering to blackout. You can get a smaller tension rod for the other window.

Great ideas, thanks everyone. I'm going to check out all of them. I especially like the outdoor shade as it could be permanent if it will roll up under the eave.

lazydaisynot, I finally got around to installing the bamboo shade I bought. I think I'm going to love it and may even put one over my bedroom window. It keeps the heat from getting to the glass which I think heats up the room worse than just the sun shining into the room. Thanks again!

How kind of you to circle back and let us know what you did! I'm so glad to hear it solved your problem. After I posted, I thought, "Hmm, maybe that was kind of a dumb idea," so it's really nice to know that at least once I had a suggestion that wasn't completely stupid! Good luck with the rest of your project!

Not stupid at all, it was a great suggestion. It even looks good from the outside.