Intel Ice Lake is on track for a late 2019 debut just in time for the Holiday shopping season and the Dell XPS 13 series should be one of the first to market with the new CPU. The actual chassis looks to be identical to the current iteration to suggest that the eventual Ice Lake XPS 13 will simply be an internal update.
https://www.notebookcheck.net/Dell-briefly-teases-new-XPS-13-laptop-with-Ice-Lake-at-Intel-keynote.393461.0.html