No one here mentioned this so I'm adding it.
You can try to use what's called a compressor stuff sack. It has four attached straps on one end and a cap on the other. When you pull the straps tight it compresses everything and make it smaller. Look it up on the web. Let me know if that works for you.
By the way, I think that someone already mentioned this a few posts back. Oh well, 'm just reiterating it.