IMO point differential isn't a great way to look at things because it's too easy for a big change in point differential to not have a corresponding change in win % or a very small change net a couple of games improvement because of distribution.
From a figurative standpoint I think 10 points is about a good representation of how far we are from a bowl team. If a team loses by 10 points (with no but what ifs) it's not a fluke. They didn't deserve to win but there were likely reasonable opportunities that were within reach to have won that they didn't capitalize on. We weren't a bowl team this year. We didn't deserve a bowl game but we had reasonable opportunities that were within reach to have made a bowl that we didn't capitalize on.
Now the big question is how likely is it we can "find the 10 points". Whether we will or not is a different question but to me there are "easy points" to be had in improving the DBs from god awful to just normally bad much less to anything better. I think there are also "points" to be had with a relatively better QB situation compared to our competition next year as many of the others are leaving and ours should, hopefully, return in better health than we had this year. I think there is also the factor that if we can have one WR step up and be a true #1 target that it will make a huge difference. There is also the "easy points" in better coaching if we can make good OC and DC hires.
I think getting back to a bowl game is reasonably obtainable next year even if somewhat unlikely, so describing that as "needing to find 10 points" is about accurate.