You can try to offer him food on his normal day. He should be fine.
You dont need to mist unless it goes down to 40% or so. My humidity sits around 60-75% and like i said, i mist maybe once a week. I use a single live plant in a pot now as i switched out a couple live plants for more plastic ones as Pat loves his plastic plants. The live plant keeps humidity good and live plants also filter out the air as most snake cages are run by limiting airflow.