If they stick with something similar to the bid book, it would be a lot more than one match. The bid book is here: https://digitalhub.fifa.com/m/3c077448dcd5c0ab/original/w3yjeu7dadt5erw26wmu-pdf.pdf
Page 141 has the draft schedule and rationale. As proposed ATL and DAL would host 6 matches including the semis (Not clear which one is US7 and US10). No city would get more than 7 matches. Of course they could go with something completely different than the bid book. I think every city that raised their hand to host knows grass will be required.