Plastic carpet protectors are practically indestructible. Even so, it might be nice to have a few ideas at your fingertips for when you decide you no longer need or want a carpet protector.
Cut carpet protector to the desired size and use as a boot tray. It won’t hold water run-off but it will protect your floors from mud and dirt.
Use an old carpet protector as temporary car mats when involved in messy activities like the beach or hiking.
Take with you when camping to use as a boot tray to keep the dirt or snow out of your camping home.
Use as a drop cloth when working on messy projects or painting a room. If you have a larger project then place a drop cloth in the middle of the room and line the edges of the room with the carpet protector. This saves having to tape down the drop cloth.