Breath-Right strips for him, and silicone ear plugs for you. That's really all you can do. I room with a guy on the road when I'm travelling for work, and he snores extremely loud. He also shouts obscenities in his sleep (which is kind of funny from time to time). It sucks, and losing sleeps sucks even more.
There's not much you can do. Unless he's willing to go to a sleep/breathing specialist, you're phucked. I have found that silicone ear plugs are the best because they mold to the inside of your ear, reducing discomfort and decibels from the outside world.
Good luck.