Grab Mothca Matte Tempered Glass Screen Protector for iPad. Etched glass is a decent option for light diffusion. TL;DR: Mothca wins on glare and durability. Tip: Install it in a steamy bathroom.

Building on the earlier suggestion, I found those premium films really disappointing. The haze percentage is way too high. The grain was just unbearable when I was trying to read... super annoying. Honestly, iCarez Anti-Glare Matte Screen Protector for iPad Pro 11-inch has much better light diffusion for sunrooms.

• super cheap (under $15)
• way less rainbow effect on whites
• doesnt eat your pen nibs like sandpaper

Jumping in here because I've spent way too much money testing these over the years. Honestly, Paperlike is mostly just good marketing. If you want something that actually works without destroying your budget, you gotta look at the alternatives. In my experience, film is better for sunrooms than matte glass. Here's what I'd look at for reliability:

• iCarez Anti-Glare Matte Screen Protector is basically the safest bet. It is super cheap, usually under 10 bucks, and it kills glare better than almost anything else. It's a PET film so it wont shatter or add weird weight to the device.
• If you really want that paper feel but dont want to spend 40 bucks, ESR Paper-Feel Screen Protector for iPad is a solid choice. It's got a great texture and usually comes with an installation frame which is a lifesaver if you're worried about messing it up.
• Another reliable one is the Bellemond Japanese Kent Paper Screen Protector. It's high quality and doesn't wear down the Apple Pencil tips nearly as fast as the original Paperlike does. Since you need it by Thursday, these are all usually on Amazon and ship fast. I would go with the iCarez if glare is your absolute #1 concern. Just be super careful with the dust during install... use a lot of tape to get the tiny particles off before you lay it down. Better to be safe than have bubbles everywhere.