Burton I agree with the others and I have shipped to and from Tony many times.
Consider that the heavier and more massive the case/box the higher the likelihood that it will get damaged from it's own weight and mishandling.
Lance uses a stout computer box with a custom foam insert and the neck and body are shipped unattached and isolated from each other.
Also consider that some foam may contain release agents that may contain silicon..... Combine this with sub-zero temps and RH of below 20% as well. I would wrap/seal the guitar in plastic, pad with foam/bubble wrap, and try to use a carton that is stout but not heavy. Personally I would avoid using a crate simply because most common carriers will use more benign schlepping methods on lighter, smaller, more carton like packages. It will save you a few bucks too.
And Tony indeed likes USPS better then the others and I do too. Remember to have a few before approaching the post office this time of year.....