Actually, the real question is whether you can maintain your interest in the story over the development time. Ocean's probably had his most successful year in his life, even with the provisional tax thing. Why on earth would he not want to keep going? If this trajectory continues, he can be a dev until he retires. Most games fail due to lack of support, then devs getting burnt out trying to make ends meet. So after Steam, it is more likely to be finished than it was 3 months ago. It's just whether or not players have the patience.
Regards the two stories, WiaB probably would've failed on it's own, and SG wouldn't have been a thing if Ocean hadn't planned WiaB. So it's pretty fruitless to imagine one without the other. If WiaB had the support SG managed, Ocean might have pushed harder to developing that first, but as it is, the second game is currently paying for the first, but the second game needs the first. The plot might not be exactly a continuation, but there's definite synergy.