Please wear formal attire. Men are expected to wear black tie's and women in ball gowns/long gowns. It's a winter ball, have fun! Dress schnazzy! Be as glammed up as you possibly can.
This is a Vietnamese-American wedding. The bride will be wearing red. So, please, please, please refrain from wearing red. It will be the equivalence of wearing a white dress to an American wedding.
SOMETIMES! It will be January and it may be frigid. Please bring a coat and try to stay warm. ;) we're hoping for snow on our wedding day.
I'm glad you asked! It will have some Harry Potter inspirations. If you have Harry Potter dress robes, please feel free to wear them.
No worries! Feel free to take the sorting house quiz on Pottermore at https://my-pottermore.wizardingworld.com/sorting-hat . Otherwise, you'll automatically be sorted into an appropriate house.