Best summer experience going into full-time interviews?

So I'm in a masters program, going into my 5th year. I was really shooting for an IBD SA gig this summer, and I had a handful of interviews but wasn't able to land an offer.

My question is, now that most summer recruiting has come and gone at my school and I have no offers to show for it, what are some internships I should seek out this summer that will position me to get interviews for full-time in the fall?

Should I look up alumni working at boutiques and send some cold emails? Should I seek out some kind of private wealth management position? Should I go abroad?

Any advice on how I should go about this situation would be helpful. I have a couple years of Big 4 internships, a HF internship last summer, and solid GPA/scores.

Thanks for the help, you guys have always been an awesome resource