@mombham your son should be fine. We moved from PA to TX just as my son started HS. He had some adjustments coming from east coast to here but adapted well. I would think already being from the south your son will be just fine. I do agree with Maine longhorn, he doesn’t want to get in the habit of comparing places. My son is also in engineering. 
In terms of the size, I told mine not to dwell on that…becoming involved with some things will make it a smaller experience.