The RPI is a very flawed metric this season, especially for Big Ten teams, because of the lack of non-conference play. The big question is how much weight will the NCAA Selection Committee give the RPI, because that's the big unknown this year.
If the season ended today, NU would be in the NCAA Tournament, likely as a #2 seed somewhere. That's about right for this year's team. NU may get a look as a regional host (even as a #2 seed) because the NCAA may want to have diverse locations across the U.S. to reduce travel.
There are a lot of unknowns this season. If NU keeps winning, that takes care of one of the big unknowns. The regional sites will be announced at the beginning of May, which will also provide us more answers. I am taking the approach for this year is to have NU contend for (and hopefully win) the conference championship, and everything else is gravy. This is basically Bolt's first year. Let's not expect the rebuild to happen overnight.