Idaho St. game to a different date.
USU only has 3 nonconference opponents scheduled (at least announced) since BYU's cancellation, so that makes sense.
I checked and all MWC teams are already booked for those dates (except UNLV is open on 9/2) unless some other teams were willing to move FCS games. UNLV also already has Michigan and Vanderbilt out-of-conference so might not want another hard game like BYU.