I am a biased Bears fan but...
Every recent GOOD bears team has done it with Defense, turnovers, and penalties (and special teams). They never look good and that's because they don't have an exciting offense. Somehow they get the job done.
I'd jump on the Bears are not that good bandwagon too if I wasn't so used to them winning games that it looked like they should have lost. That's just the way they have played in the Lovie Smith era. THEY DIG DEEP!!
I think at least one more year of building. The O line needs serious help. Great QB, plenty of talent at RB, TE and wide-out. The secondary needs some high caliber players too. With a better O line, we might get to the same caliber offense as the 'Greatest Show On Turf'.
I may be getting a bit more optimistic, but my pre-season guess was 6-10.