That's certainly gotta be the plan here. But the problem is, it's going to be tedious. Plus, I'm not sure it's going to work, that the sci fi audience overlaps with the cop show audience enough.
Grimm is showing the right way to do this sort of thing - just use the fact that the main character is a cop to streamline his involvement in the actual story. Just having the connection be Michael's ability to see clues from one reality to the next is uninteresting and thin. Maybe it will go somewhere.
You can't use the BBC as analogous to anything in American TV because the BBC has a guaranteed income from the TV tax they have. Can you imagine Americans sitting still for that? Hah!
No, American TV has to duke it out in the free market. That gives us a large range of business models and show types, from the mass market of broadcast to the more specialized realms of basic and premium cable. There's a lot of good quality stuff in the mix, so it's a perfectly functional system.
And HBO does still do miniseries, bless their heart. They can afford to - they are financed by premium subscriptions, not ads - as a rule of thumb, ads give you the least money-per-viewer, basic subscriptions gives you more, premium subscriptions give you the most. The more each viewer is worth, the more you can blow money on catering to their tastes, even when they are pricey, like miniseries are (no chance to amortize the cost of a show through a long run). HBO has done some very good miniseries, some of which are the best things on TV ever, but they don't seem to have much interest in sci fi.
And there are also shows (especially on cable) where the showrunners declare "we're running X seasons and then we're done," and they do get their way, regardless of ratings. Breaking Bad and Sons of Anarchy are both doing that.
They'll end up with more seasons than most shows get, but that's what the showrunners had in mind. There's a good reason why they wouldn't plan for only two season runs - they want to keep their jobs, not to mention the jobs of all the people working for them. Who wants to be unemployed in this economy? And TV is always a tough business to stay employed in. Why choose a two-season premise when you can choose a five- or six-season premise instead? There are all sorts of ideas possible, and the premise really determines how long the show should run.
Also, "TV stations" don't make anything. Networks and cable channels do. (Usually they are owned by some megacorp - SyFy and NBC have the same parent company for instance.)
