Overcoming Absymal GPA/Non-Target for Lateral Hiring

I have about 1 year of full-time experience and a summer internship in IB/M&A with a small boutique. I’ve done very well in this job and have been a high performer since my internship. Deal flow is excellent and I’ve learned a ton. I was able to take on associate responsibilities as well and crushed it. I’m confident my peers and superiors would give glowing recommendations.

I’m now trying to lateral to a MM (or any larger firm), but I’m seriously hampered by my background from a non-target state university and an absolutely abysmal 2.1 undergraduate GPA. I can explain it away a bit as there were some major external factors at play and I worked crazy full-time hours to put myself through college. I also was very involved in leadership roles which is good, but nonetheless it is a major blemish especially coming from a non-target. It’s tough to even get interviews from applying online and when asked about it in interviews, it is tough to overcome just because it is so low.

I love IB, but I really don’t see a future for myself at my current firm beyond a couple more months, nor would I want to stay if there was. This is for many reasons that aren’t so relevant to my post. I’ve considered exiting while doing some post-grad coursework to get high grades and possibly doing an MSF/MFin or working towards a CFA (or all of the above) if I can’t land a lateral gig. MBA is likely out given GPA. BB would be ideal, but obviously MM and more reputable or well-known boutiques would be the goal realistically.

Does anyone have any tips as to how I can overcome my undergraduate record and propel myself into a career at a larger bank?