Halloween 2018 added 1.9x its SatSun. Halloween Kills added just 1.6x. With a hybrid release like HWK, and even worse reception, HWE will probably aim to add 1.5x for ~20OD+20SatSun+20*1.5rest=~70M.
The Halloween holiday does offer some mild help, but it’s just one day which isn’t even a school holiday compared to 2-3 weeks or school break for Xmas, and it has less cultural oomph as a holiday. Doesn’t do much to counteract the extreme front loading of a poorly received slasher fan franchise.