It's hard to say what the exact record would be due mostly to turnovers and their random nature.Really makes me wonder what our record would be right now if we had a legit DC.
Assuming we improved a yard per play in this hypothetical scenario we'd be at 5 yards per play allowed, about 40th in the country. For reference that's slightly worse than Illinois and about what we saw from Nebraska a few years ago. Certainly not a great defense by any means, but within the realm of plausibility for our scenario.
With our offensive production, though, that would put us at +1.2 yards per play this year. That sort of differential would have us somewhere between 0-1 losses given our schedule, again depending on things like turnovers, red zone production, etc. As many have no doubt guessed, it'd make us approximately Iowa.