I've had too many great hatches where the humidity never got below 60% the entire time. The air cell and membranes can handle a pretty wide range of climates. Broodies hatch eggs in both Arizona and Florida just fine. The only time I've seen big losses from humidity is with a sudden, drastic change after pipping.
Just as I had given up all hope one of them actually did! I hate that I had eight to begin with and only one success, but I will do better next time. Thank you everyone for the advice and tips! It will help with my next hatch for sure.