Well the season finale left it wide open for season 3 so if it doesn't get renewed we won't have any kind of closure. I know it is a quirky show but I enjoyed it.
And now that they've established the 3 main characters as all immortals (funny since none of them started off the series that way), they can tell any story they want to in the timeline they've established. They can pick up right where they ended, they can jump to whatever mid-date that was when the infertility epidemic was in full swing or they can go the full 30 years into the future to the plague that's wiping out immortals.