During a slower time you could pretty much show up (except dinner). You can make a PS from your room the day of, or even the evening before. It does mostly depend on your group size too. We just returned last week and did make a breakfast PS for a party of 8. Glad we did because the line was long at 8:30AM when we arrived. When we were there in July (WL) we showed up for breakfast every morning and had no problem for a party of 3 (we do however, arrived at openning/7:30AM)