You go too far south and the risk of having too many Central American fans in the crowd supporting the other team.
Also ... Canada is top of the table killing everyone in the cold, you're not making sense here.
In the WC all teams will be playing in pitch-perfect conditions. No point in playing in sub-standard conditions for WCQ. If the USMNT is that much better than Honduras then a game in Miami at 75F even with deep Central American support shouldn't faze them.