According to director (and producer) Ariel Vromen, they had a test screening on the movie and it will just need a month to have the movie finished. He also announced the “The Iceman” got officially selected to both Venice film festival and Toronto Film Festival.
Sumatra Film official page has already a link to what may be an upcoming test scene/trailer for the movie. It’s directing us to a 404 page, but it worth checking it on weekly basis for some trailer news.