Many people expected a GeForce GTX 1080 Ti announcement at CES, but it did not happen. This might have been due to the fact that AMD did not have a Vega announcement either. Whatever the case is it looks like NVIDIA has selected PAX East as the grand stage to announce the card. PAX East starts March 10th.
This information comes from a MSI representative, who also said the GTX 1080 Ti would be available from board partners at time of launch.