If Homura is worried about Madoka coming along, why can't we just suggest that Homura come along, too, and keep Madoka safe?
I mean, between Sabrina, Mami, Homura, and Sayaka, Madoka would be very well protected. And it's not like we'd be meeting anyone we don't already know (and don't know the abilities of).
That's an interesting idea. Of course, we might want to avoid telling both parties that, since if they both decide to hunt in Mitakihara and run into the same Witch, it could be problematic...
Plus, we do owe Kyoko more, right?
...I just had a thought, though I doubt it's a good one. We could invite Kyoko and Yuma along for the trip, but then I realized that with Mami along, it would be super-awkward unless they could reconcile at the start.