It may be possible without an on campus stadium. USC does it. UCLA has done it as well. Heck, Alabama did it for decades. And they are upgrading Dolphins Stadium (or whatever its called these days). But, it absolutely is not possible without facilities upgrades and fan support. Miami has always had lackluster fan support, and it's grown worse and worse. But even in their heyday, they never drew huge home crowds, unless it was a big time game like FSU or Notre Dame.
They need a great recruiting staff, a coach on the level of Nick Saban, upgraded facilities, and better fan support. Without better fan support, I'm not sure the other 2 are possible. With Miami, it seems like everyone but their fans want them to be great again. I don't see anything from that fan base that makes me think they take their football seriously.