Here's an AP story in English about Belize's intentions of hosting their World Cup qualifier in either Houston or Los Angeles. Apparently there is no stadium in Belize capable of hosting such a match.
As far as the possibility of there being a huge pro-Mexico crowd there, well, the story doesn't go into it. I'm guessing it could work out to Belize's advantage if they get a cut of the gate revenues. Maybe that's why they are so happy to seek a location such as Houston and Los Angeles.
Also, the Belize FA president said in the earlier story I linked that they were just happy to have reached this stage of qualifying.