According to a proposal deck sent to the N.B.A. and the W.N.B.A., which The New York Times reviewed, MGM envisions a fully quarantined campus, essentially one full block of the Las Vegas Strip, where players would live and play out whatever schedule the leagues want. The athletes would be joined by their families, league and broadcast media employees, as well as the staff and vendors needed to serve them, with access to lounges, spas, restaurants and all the other perks the resorts offer (yes, even gambling). Sports leagues have explored any number of options for restarting their seasons, and various news media reports have floated cities like Las Vegas, Orlando, Fla., and Atlantic City, N.J., and even the states of Hawaii and Arizona as possible locations for games in a semi- or fully-quarantined environment. But most league executives have been publicly noncommittal about their plans.