While I can't understand someone simply
refusing a sleep study, you do also have to keep in mind they are pricey and not always covered by insurance. We found that out the hard way and were out almost $500 out-of-pocket!!
That said, we are now at the point of splitting up on vacation. Our last family trip to Disney, we were all in one room at POR. We survived, but barely...

I think being absolutely exhausted at the end of the day helped a lot. This year's vacation is to Colorado, and I've rented a lodge/house so we all have our own rooms! (most nights at home I end up on the couch...I have ear plugs but they irritate my ear canal after too much use). Next trip to Disney, we will get two rooms (to be fair, it's also because we have three boys who are getting bigger and one room is just TOO cramped!). I guarantee you I'll end up with my boys in their room!
Oh, and I wouldn't worry about not hearing a fire alarm while using ear plugs.....they drown out
most noise, but not all, and let's face it a fire alarm is designed to wake the dead!! (I can hear a simple smoke alarm when I'm using them).
Good luck and have a magical trip!
.