My dad owns a furniture repair business and has kept pieces of furniture in cold storage for months without any real damage to anything. The worst thing you would really have to worry about in regards to variable temperatures is when you actually have the guitar put together. When the weather gets colder and drier, your guitar will shrink ever so slightly, which will require a little adjusting of the truss rod and maybe checking the intonation a little bit. When the weather gets warmer and a little more humid, that's when things expand a little bit. The worst story I have ever heard in regards to temperature damage was a story Jaco Pastorious told about a double bass he bought when he was a younger man in Miami. He woke up one morning and found the bass had swelled to the point of falling apart due to the extreme humidity.
If your parts have been in any extreme cold or heat for a stretch of time, bring them into an indoor environment and let them sit about a week to ensure that things have expanded/contracted to a uniform level.