I have two families come 30 mins before regular opening and charge $5 extra.

Like Babydom mentioned, make sure you okay with it as super early. I used to have family come 6am and found hard in Winter when trying to clear snow for car to get on driveway. 6am opening likely mean 5am wake up for you and maybe earlier if clear own driveway. Not so bad if you can roll out bed at 5.45am and just quick shower and ready.