I think it is more reasonable to wait until Jan 26th to draw the final inference. Self-posted results from last year indicates that most visit invitations were sent around Jan 20th, but this is because last year Notre Dame started their spring term one week earlier (Jan 10th) than this year (Jan 17th). So I guess the review process for PhD application also moves accordingly to one week later this year. Anyway, don't give up your hope and best luck!