The available staff has never appeared to affect the number of houses, scare zones, bars, shows, etc in the past. BGW has historically seemed perfectly happy to open nearly deserted haunted attractions almost nightly.
If staffing is bad enough to where the number of houses being run must be reduced, it could be a good idea to run an entire bonus house or two with no actors at all, and brand it as something new, a "themed experience" of sorts. Almost like when they did day-time walkthroughs of the houses many years ago, something where they don't need to have a line or anything, just a continuous cycle of people walking through a themed area for a little extra experience since it won't be as many houses.
Hell, this even opens the event up to those people who don't enjoy the scare-actors portion of it (the people who get too scared) and act as a good introduction to haunted houses for kids at that age where they are curious but as parents you don't want them having a breakdown in their first house from someone jumping out. This also acts as a good people eater, as the major downside to not having as many houses is the lack of people being occupied in something, so just having some areas where people can walk around and see some decorations, but in a tighter environment than can be achieved in the normal walking paths of the park to get that extra tension and atmospheric boost, is a nice bonus and could be done with little extra effort from the team.
I think they should do this anyway, or at least resume daytime/pre event hours walk throughs of a house or two. That unstaffed daytime walk through of Pompeii years ago was what finally convinced my kids to start staying after dark, and finally allowed us to start enjoying the event as a family.