With the size of these storage bags, you can fit a lot of stuff in these bags. The size being (39.4 x 19.7x 5.9 in) you don't need to worry much about finding a place to store your extra blankets and throws. This will do the job fine.
If you are looking for a specific bag to store specifics into then these bags are a must. You can store a comfortable blanket and a pair of soft socks and a good book or two. And some odds and ends and then just store it under the bed for a rainy day. Or you can use it for actual storage.
you can even use these in a guest room for an extra blanket and soft socks and a snuggie and even for storing a zipper bag with some extras like a toothbrush and some toothpaste and a few things a guest would need.