I’m guessing you mean the Elliott Grand Hyatt; there is not a Park Hyatt in Seattle. You don’t need to stay any extra nights. If you have ‘Qualifying’ incidental charges to your room on an award or Priceline stay, you will get a stay credit. A phone call will work, but parking at the Elliott will not since it is contracted out. Also have dinner at the hotels restaurant, 727 Pine, it is very good.