I'm not sure how the social program works at UIUC, but I applied to the clinical program and know that they do not hold in-person interviews prior to making a decision, just hold a recruitment weekend in mid-late March. Perhaps if social works similarly it might be helpful to attend? You still have a bit of time to discuss with your POI, but it might be a nice way to meet students who are seriously considering attending and see the campus.
Also, I wouldn't rule out the possibility of being reimbursed or funded to fly out for a visit. Even though your POI has not started their contract, if the department approves of his/her move to accept a student, it is quite possible for them to offer financial support, especially if you are seriously considering attending and your POI has agreed to accept you.
Best of luck!