I'm voting 8+
From what I've seen from the defense so far, and the slow, but noticable improvements in the offense, I think the following games are all reasonably within reach for us to win:
Iowa
UCLA
Maryland
Illinois
Rutgers
Wisconsin
Win all of them, and we're at 8 wins. I also think it's possible we pull an upset in one of our other games (IMO Michigan, ironically, might be the most likely game for us to win out of the 3):
Michigan
USC
Penn State
Michigan got stomped by Texas, though maybe Texas is finally back, and let Arkansas State score 18 and only won by 10 points, so we'll see how they do next week vs USC.
USC has only played 2 games so far, but do have a top 25 win already, and shut out Utah State 48-0. Their game vs Michigan will be pretty telling I think.
Penn State has also only played 2 games. They beat West Virginia pretty handily, but only beat Bowling Green by 7 points, and allowed bowling green to score 27, so it's hard to say if they really are as good as their ranking. We play them the second to last week of the season, and we will have had 3 common opponents by that time, so we'll have a pretty good idea how we match up going into our game I think.
Honestly, so long as our defense continues to play like they have, I think they'll keep us competitive in every game, it will be up to the offense to execute to bring us over the finish line and win.