Probably keep it as indoors as possible. The opening murder-suicide, the bathroom where Dani hallucinated her sister and started deforming, church with the skinned face, the chicken coop with the blood angel, the burning temple at the end, the impregnation (jk). They could probably get away with a daylight setting if they cover the room in a loooooooot of foliage/moving branches and spotlight a prop to keep the eyes off the walls (so, a dinner table maybe, or a giant rock with the smashed elders and Dani's sister, and obviously the maypole with all the people who's faces are shifting around thanks to the drugs). In the case of the maypole, they could probably shine a bright floodlight from behind to make it seem like the sun is right behind it and cover the sides with foliage, which would also go a long way to disguise any under-dressed walls. Alternatively, just fill that puppy up with strobe lights and say that that's because they're tripping out on drugs.