They might actually be more accurate with thinking October is going to busier than it has been in years past. Halloween night's MNSSHP sold out 3 weeks earlier than last year. It is on a Saturday so that boosts the turn out a bit from locals but last year Halloween was on a Friday. 1 week earlier sell out: sure - but 3 is an offly big jump start.
They probably will lift some of those dates in early October but the last 2 weeks will likely stay.
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And as a total aside: out of curiosity I brought up this topic with a few CM friends with families. 2 families said it stinks/they were annoyed, 2 said they avoid the parks in the Summer/until November-ish, 1 said you "couldn't pay me enough" to take her family this time of year, and 1 said he just works around it.