That is a huge problem for us as well. Any time we travel. I can't fall asleep on a plane because I have to be on high alert to elbow him if he falls asleep so that he doesn't become the mockery of the plane.
I too am a night owl and prefer staying up a little later. I tried going to bed earlier but then when HE fell asleep in the living room waiting for ME to fall asleep in the bedroom, his snoring kept me awake - so I left him on the couch!
The ONLY savior for when we are at home is that he is a

and sleeps at the firehouse on average 2 - 4 (sometimes 5) nights a week. So I don't get SO crazy on the nights that he is home because I know it truly could be worse and also because I know the other guys in the bunkroom give him hell over it as well.
I will have to look into this mouthguard as well. He went for the sleep study, found that he has sleep apnea but will not get the mask to fix it. He sleeps on his stomach 99% of the time and said he can't sleep with something like that on his face. I was tempted to give him the choice of the mask or me covering his mouth when he slept but thought better because that would just NOT end well, lol!
Thanks for the tips!
Kat