At the end of the day, I think there are a few determining factors about whether Day 1 will be cancelled:
1) The ground conditions in La Grange and if the fairgrounds are even usable
2) The threat of severe weather during the Day 1 ride that'll put rest stop volunteers at risk
3) The threat of severe weather overnight in La Grange that'll put everyone at risk sleeping inside of a bunch of lightning rods wrapped in vinyl
After looking at the updated weather projections, I have a feeling the third one will play a big role in the decision making.