I have a crack that forms at the corner of the door frame that leads to a bathroom at home. It opens up every winter and closes up in the summer. Also, in the winter, the door frame shifts just enough to keep the latch from hitting the hole in the plate.
This room is a first floor bedroom and bathroom on top of a crawl space and is standard 1960s construction with dimensional lumber joists. Above is the attic, ranch style house.
Inside is kept at 70F and humidity is about 30%. There are a few other cracks (trim joints, etc.) that open up in the winter too, but this wall one is the most noticeable.
Any tips for addressing this without major work?