Many thanks to mgb for the heads up!
Matthew Ross, director of Siberia, left for St. Petersburg along with the cinematographer on May 19 according to the comment he posted with a photo on instagram. From an older photo on his instagram page, he was in Winnipeg 13 weeks ago, I am assuming to scout locations and prep for the Siberia shoot before the cast arrived. It is not clear at this point if he is heading to St. Petersburg ahead of the cast to scout locations and prep for the rest of the shoot or if that work has already been done and the cast will be joining him shortly.
Update: Many thanks to mgb for the heads up!
Many thanks to theimaginehunter, Eric Koretz the cinematographer for the Siberia shoot, for sharing a photo from St. Petersburg on instagram.