Inside the tent we used to use a moving blanket. It worked great, since it was padded, packs easily, and you can throw it in the washer when you get home. Plus if you camp where it is a little chilly in the fall, it keeps your feet warm in the morning. Almost forgot, very durable too and the come in different sizes.
Another plus, is that I used to keep it in the back of the SUV to protect the carpet when not camping.