Here's my story from the UK.
Like so many others have said finding the appointment is difficult. This morning (10th June) I have been conditionally accepted.
I am in California on vacation in October and can't find anything during my stay. SFO nothing till December and LAX has nothing at all. I have though found an appointment in Chicago during my stay so looks like a day on a plane for me.
Haven't given up hope of a Californian appointment yet as both Las Vegas and Long Beach have appointments up to September then nothing in October. Seattle was also the same too. I wonder if the appointments haven't been loaded yet?
Guess I'll need to keep checking for openings.