Is it better to climb the Grand Teton in a day or use an overnight permit at the Lower Saddle?

For most parties, the overnight is the better climb. Camping at the Lower Saddle at 11,600 feet splits roughly 7,000 feet of total gain into a manageable approach day and a short summit morning, puts you two hours from the technical climbing at first light, and gives altitude a night to settle. The Saddle has flat tent platforms and melt water in season. The cost is the permit: overnight camping requires a backcountry reservation, the advance window opens January 10, and peak dates go fast.

The single push needs no permit, which is its main appeal, but it demands a pre-dawn valley start and the fitness to climb technical terrain deep into a huge day. On the standard Owen-Spalding route (5.4, with two pitches of roped climbing and a rappel or downclimb to descend), tired decision-making on the descent is where day parties get into trouble.

Weather is the fixed constraint either way: afternoon thunderstorms are common and the upper mountain is badly exposed to lightning, so be off the summit by noon. A Saddle camp makes that deadline comfortable; a day push makes it tight.

If you want the classic experience, the Upper Exum Ridge (5.5-5.6, 13 pitches of quality granite) is the step up from Owen-Spalding, and it is far more enjoyable on legs that slept at the Saddle.