Barbarian's Bookworm

When Hermione Granger wakes up on a strange ice planet, she imagines nothing could shock her more... and then, there's a parasite placed into her body, meant to keep her warm and alive. She accepts it, accepts her fate, accepts life in the tribe... and then, a strange alien returns to the tribal caves, and she has no choice but to accept that this is no longer a fun learning experience about another culture, but instead, a fun sexy learning experience about herself.

The Ice Planet Barbarians x Dramione Crossover you didn't really need or ask for, but you're getting all the same.
SPOILERS FOR BOOK 1: ICE PLANET BARBARIANS. You do not NEED to have read it, but I do recommend it!