Taking filming schedules and post-production work into account, a late fall/early winter release of the next batch of episodes would make sense.
Season 3 is set to begin shooting this month in Vancouver.
Although no premiere date was announced with the renewal news, we may want to expect Season 3 to release in the same window as the first two seasons.
Seasons 1 and 2 first aired on Showcase in mid-October and then concluded around the end of the year; Season 3 may follow the same model and premiere in that timeframe.