I think you're over-thinking this. Trump is acting like a fool. The best response is to just laugh at him when he acts like a fool.

Sure there are foolish things he does that has serious consequences, those need a serious response. This isn't one of those things.

On this? Laughing at him is the best and most honest response.

He said he might also rename the Atlantic and/or Pacific Ocean too. Someone needs to tell him it's a good idea and he should definitively do that. Then we laugh at him some more.