While we play through anything and solider on,
wet soggy feet or flimsy light costumes on cold days just sucks.
Layers are a good thing and smart.
Waterproof boots are a VERY good thing.

Pay attention to the weather and dress accordingly.
In the last 10 years, most of which were held in January:

the weather has ranged from bright and sunny to snowstorms
the temp has ranged from 40+ to subzero
the wind has ranged from calm to “blustery”
the snow coverage has ranged from green grass to north pole depths
the fairways have ranged from 24″ hard pack to 6″slushy
and the non-groomed “rough” from wet slop to 4 feet of powder

If it’s sunny, bring sunglasses. It’s a big snowy field.
An extra pair of socks / boots is always a good idea for the afterparty