Honestly, I don't know. I know keeping them out of that range for a couple hours can kill them. Maybe you might want to consider heating that particular room up a bit before you pull the eggs out? I'm sure the fewer changes in temperature the better.
With my whole 1 clutch experience, I never really worried about mold. I practiced making sure the vermiculite was just the right consistancy. If I noticed too much condensation on the walls, I took a paper towel and wiped the excess off. So I have no experience with mold. I think if you provide the right conditions you wouldn't have to worry about mold. Sometimes even in perfect conditions eggs mold, but I thought that was more likely due to an infertility issue. Again, I hope some others with more experience can comment on this for you.