S.F.
If they're presents from Grandma and Grandpa, and you're at their house Christmas Eve, I see no reason why THEIR presents can't be opened then. Santa will still visit your daughter that night and leave her presents for Christmas morning. I don't think it would ruin the excitement. If anything, I think it will make it more exciting.
Or, if that's not ok with you (and it sounds like it isn't) perhaps your parents can pop over early on Christmas Day for a quick "grandma and grandpa" opening before their breakfast.
Last but not least, you may consider an entirely different day on which your daughter can open her grandma and grandpa presents. With my husband's family, we used to have a Christmas gathering the weekend before Christmas since they traveled for the actual day. Again, this seemed to extend the holiday joy rather than take away from it.
You might try it one way this year and see how it goes and then try it a different way next year. Honestly, do you remember Christmas from when you were 3? Probably not. I think you have a year or two to work out the kinks.
Good luck.