We do the same as Becky, and I was going to suggest that too, to bring some stuff from home. Little things. We only take the things she has in her bed, but that's quite a lot of things
She has her dummies (at least 3, the more the better according to her), her teddy rabbit, her teddy teletubby, her cuddly cow blanket and her music playing clown. Oh, and her own pillow, we always bring that with the same pillowcase she's had for a few days before we go away. I used to always put all her things in the travel cot before bedtime, and then put her in there to play with her sleep things for a while just to get her accustomed to it and that always worked great for us.
We're going away too and now I have the same worries as you but because she's now no longer in a cot, but in a toddler bed. Doubt she'll nap there, but who knows?
Good luck to you!!!