I don't have a dog... but I've heard of those toys (Kong? maybe?) that are like puzzles for dogs. You put a treat inside and twist the pieces, and the dog plays with it, chews it, manipulates it, etc while trying to get the treat out (and then is rewarded with the treat, of course, when successful!)

Here's an article that talks about the Kong (which doesn't look like what I imagined at all!) and a couple other similar toys:
https://gizmodo.com/5913008/the-6-be...og-really-busy

You could also try to tire him out while you're there with hikes, swimming, fetch, etc. That might help him be a little more chill?

Have fun!

(Edited to fix broken link - sorry!)