Peace Corps Volunteer with Terrible GPA

I am currently a Community Economic Development Volunteer with the Peace Corps with hopes to attend a top business school after completing my service. I have always had an interest in the power of the financial markets and constantly read books and articles on these topics with constant fascination. However, due to a few factors I earned a terrible gpa (~2.5) and needed 5 years to graduate. I should say here the university I attended was a state school with a top 20 undergrad business school. Despite this, I had a variety of solid internships throughout college.

Upon graduation I worked in strategy for a real estate investment firm for a year and as an energy consultant for 6 months before starting Peace Corps Service. In both jobs, I was told I performed very well and maintained good relationships with everyone to ask for recommendation letters, and I believe they would vouch for my stellar work with no way of knowing for sure.

A couple things I have already read about: 1. I know I would have to spell it out as to why I performed so poorly throughout college 2. I would also have to connect how the Peace Corps relates to my desire for a MBA 3. The GMAT will be a big focus for showing that I am better than my gpa.

My question is given my background, current role, and terrible gpa, is there any chance that I will be able to make it into a top ~20 B school?

If so any recommendations as to which schools based on my experience?

Is there anything I can do in the meantime from a Peace Corps country to improve my chance at getting into one of these programs?

Any advice would be greatly appreciated!