At hotels, I do as Denise has suggested and ask for extra pillows. I am also extra careful on vacation to make sure not to eat for 5 hours before bed to avoid such a situation... sucks, I know :(
Also, if I'm staying at someone's house, I usually nab a couch cushion (the big ones that you sit on or the ones that go behind your back) and that helps quite a bit. Most people are quite understanding, but if it seems strange to ask or something, just grab one after everyone goes to bed.
Have a nice holiday :)