With planning, you can reduce the likelihood of triggering a migraine. Firstly, don’t skip meals earlier in the day in anticipation of a large holiday meal. Skipping meals may in and of itself trigger a migraine. Avoid your food and drink triggers entirely, if possible. If you don’t know what they are, try to stay away from cured meats and aged cheeses (skip the pepperoni and cheese plate), hot dogs (pigs in blankets), pizza, highly spiced foods, deli meats, and monosodium glutamate (MSG). Opt for white wine or light-colored liquor over red wine and darker liquors. Or no liquor at all. Try to stick to the most natural and unprepared foods, veggies, fruit, simple grilled meats, and breads. Eat chocolate and other sugary things in moderation.
As for the smells, if you’re close enough to the hostess, you can contact her ahead and talk with her about your problem; maybe she can limit the scented candles. Let your friends know ahead of time that perfumes and colognes may set off your migraines, and ask if they can refrain for this event.