I used to live in Alaska, and now I live in Arizona. Extremes: check. I've had good luck with both shipping and receiving and I believe that patience is the key. If the guitar/body/neck is well packed (which Warmoth products are), it's unlikely (not impossible, but unlikely) that it will be damaged by climatic changes during transportation. It's the sudden ripping open of the box when it arrives that does it in. The internet is full of heartbreaking accounts of people watching their finish check before their very eyes 'cause they were understandably excited about the arrival of a guitar or other wooden instrument. Bring it inside and leave it. Make it a religious exercise of self deprivation or whatever you have to do, just give it time. When I'm shipping guitars, I typically send the following link to the recipient because I think it covers the situation nicely.
https://artisanguitars.com/faq/temperature-warning-why-should-i-wait-24-hours-open-my-newly-delivered-instrument
The meat of it is this paragraph:
First... feel the outside of the shipping box. Is it cold? Hot? After allowing the box to acclimate to your interior climate, place your hand on a wooden table in your office or living room for comparison. Does it feel like it is the same temperature as the shipping box? If so, open the box and feel the case through the protective plastic bag. Does it feel cold or hot? Once again, compare to some wooden furniture in the same room. If it does not feel like it is the same temperature, wait to open the case. If the temperature feels the same, it is safe to remove the plastic and open the guitar case. Feel the guitar itself... if it still feels warm or cold, close the case immediately and let it sit awhile longer, otherwise it is now safe to play!