Fast N Vast Auto- 2nd grow

I will be harvesting sometime this week. I flushed a few days ago. Cloudy trichomes with some amber and mostly brown pistils. This is the 2nd time I’ve grown this strain and it’s very easy to manage. I have two of these plants and I’m looking forward to rollin something soon. One question...I’ve got low humidity and will be drying in a cardboard box a I have other plants still growing in my tent. How do I either increase the humidity or make sure that this dries slowly enough.