In the case or not...I have multiple guitars (acoustic and electric) that are kept in their cases when not being played. I have heard and concur with the advice, the case is the safest place to keep a guitar when not being played. Chicago winters challenge the humidity issue, and even 35% house humidification during 0 - 15 degree weather results in significant window condensation. A room humidifier is also used in my guitar sanctuary at night to boost humidity levels. I keep MusicNomad sound hole humidifiers and Dampits (larger model) in the peghead compartment of each acoustic and single Dampit in the electric. I do use distilled water in these devices, as recommended by MusicNomad, to avoid scale buildup from our hard water.
I do not keep any guitars outside of their cases for the humidity issues and my Brittany Spaniel's rambunctious behavior during various times of the day. I try to keep regular practice times, then keep them safe when finished.
Extended storage periods does make me think of relieving string tension. Is there a recommended amount of string relief, such as half-tone, full-tone, or perhaps more?