Usually under "videos" they'll have something that says "Backstage stream" or something like that. It's not up yet..but look for it in about an hour.
Jackie Wong's tweeting from the men's practice (and posting in the link below):
http://www.rockerskating.com/news/2017/1/18/2017-us-championships-practice-notes
Sounds like Nathan is killing it in practice.
Thank you for the link