I don't quite get this tbh. Messi, Agüero, Higuain, Di Maria, Mascherano, Zabaleta all live in Europe for years. Similarly Alves, Marcelo, T. Silva, D. Luiz, Hulk etc. Why would they be more comfortable with the hot and humid climate?
I don't think it's true that European teams struggle in America. A European team has never won it on North / South American soil but that's more coincidence than anything else IMO, like "Messi hasn't scored from open play in England" before the CL final in 2011. The last 2 times in 94 and 86 there were 3 European semi-finalists. Just coincided with Romario's Brazil and Maradona's Argentina. In fact in 1994 7 out of 8 quarter finalists were European. lol And that was one of the hottest World Cups ever.
Haven't Spain already broken the "no European team has won it outside of Europe" curse?