The Winter Solstice, in Pagan and Wiccan practices, has a great many rituals dedicated to it.

Much of them Irish Celtic in origin.

I understand you're thinking more along the lines of vampiric, but maybe you should look into the rituals of old and see what you can do with them?

Meáand Geimhridh is the Irish Celtic name, apparantly (had to look it up since Mabon, or the Autumn Equinox, came to mind instead), though I cannot find correct ways to pronounce it.

My guess would be mee-ahn Gimree, but yours is probably just as good.