Short answer...probably. I always use the crowd forecast calendar at https://www.isitpacked.com/disneyland-crowd-forecast-predictor-calendar/
Always parades. Christmas decorations are delightful. Download Disney app and for 5 dollars each, get your fast passes without walking to the attraction
Holidays are extremely crowded.
To be honest most of the time it is crowded weekends or weekdays.Not sure about the second question
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