Originally Posted by PolyLinguist
Another poly friend then? Presumably she is poly, after all.
Pretty big presumption, there. And even if she IS poly, how on earth is that relevant to who is available to spend time with one on a holiday? Whether poly or mono, other lovers or just friends might have their time already scheduled. Assuming that the gf could find someone to spend the holiday with (with the implication of "if she really wanted to") is a false assumption and does not help the OP. It doesn't take away from the fact that the gf wants to spend time WITH THE OP, or help the OP figure out how to schedule their time.
I agree with everyone else that said that you need to figure out what you want and go from there. There may still need to be compromises (though hopefully everyone who cares about you is respectful of your need to get work done) but at least you wouldn't be coming at it from a perspective of, "How do I make everyone happy?". Rather, you'd have the attitude of, "How can we all work together to make each other the happiest?" Because it should be a two-way street- they should be working towards your happiness as much as you work towards theirs.