A few details - the event is over 2 separate weekends in March, the days change every year and the FB page seems to have the most up to date info. I stayed in Mexico City and hired a local guide that had a car.
It might be possible to stay in Tultepec. The town is small and I'm not sure if there is a hotel - maybe airbnb. The drive from DF is about 30 mins, so its not terrible. You could rent a car and stay in Mexico city.
*edit I had pasted the FB page - not sure why it got stripped out