I'm worried they will dry out and they are oh so moist right now.
Are you kidding ... I would eat them now and serve something else to guest tomorrow !Or, probably best to refrigerate in an air tight container, bring to room temp before serving.Put a lock on the fridge overnight to keep prowlers out.Bacon brownies are making my heart flutter - good luck with them. (maybe post your recipe ... please)
To be safe I'd refrigerate them unless it was just for me. Try the trick for sandwiches. Wet a paper towel and wring it out well and spread them over the top before you seal the container.