Question about Breakfast of Champions

Hey guys! I had some questions about the New Year's Breakfast of Champions, a few work colleagues told me about it, but when I looked it up I was a bit confused. It seems to be an all day thing on New Years Day that goes from 4am-9pm?

Do most people normally go at the start (4am) or later in the evening (5pm and later)? I'm busy during the day unfortunately.

If people normally go at the start (4am), do most people normally go to some other party/event for New Years Eve? Is there a common or connected event for the night before?

And, finally, I couldn't tell if it is an indoor or outdoor event? I'm wondering if I need to wear layers or will we be indoors mostly and dancing so no need for too many warm clothes?

Thanks for any info!!