Terrible undergrad record, but an exceptional (albeit short) grad record at a lower tier school. When would I have a chance at applying to better schools?

[StoneWhite]

I graduated in 2017 with a 2.6 undergrad GPA in poli sci and history. Started the MPA program at the local university last semester, but looking to go somewhere else. To be frank, I don't feel that this is the right school for me. I don't feel challenged, that I'm gaining new skills, or that it will advance my career in any way- it seems like a lot of my classmates are trying to get into the professional position I'm already in. 

My ambition is to go to one of the stereotypical DC or NYC school for international relations that the IR forum is filled with: GW, NYU, Columbia, American, Georgetown, etc. 

Now I've only taken two classes but received an A in both. And with most of my tuition taken care of through work, I can afford to take as many classes as needed.

How many classes/semesters would I need to take to be taken seriously at the schools I've mentioned above? Assuming the other parts of my application are up to par.