To actually WIN the NC. We're not talking about that - we're talking about whether a 1-loss ND can MAKE the CFP, not WIN it with Kelly.
It's actually pretty clear ND is viewed as a CFP worthy program by the CFP committee - they've made it twice (and would have made it easily in 2012). Performance in those games doesn't really matter - see Oklahoma continuing to make playoffs despite 20 years of underwhelming in BCS title/Playoff games.
Every year 4 teams get in. If you have quality wins, and a forgivable loss, you can clearly make it even as a non-champ/non-champ game participant.