>>3076352Daemons also burn under sunlight, so they only needed to hold on long enough for the sun to rise. Noctis also overloaded the crystal to the point it shattered, and the anti-Scourge cleansing magic explosion was pretty damn powerful - it took all the magic contained in the crystal, Lucii ring, and Noctis' own body and soul. The only time his group was actually in danger was the time window between Noctis' death and the explosion/sunrise, since he was the one powering all their magic and weapons.
And
>>3076355 said, Noctis sounds absolutely certain they'd live in every Insomnia conversation. He also says "somebody has to save you three" when asked if he's still willing to go on in Chapter 13, so thematically, saving his group was clearly a big motivator for him too.
