EPS to high res JPG

I am trying to write a script that can batch EPS to high res JPG (20 MP and over). I can set this up basically, but I have run in to a few problems.

The maximum scaling in jpeg export options is 776%, but some of my EPS files are very small in size - so 776% does not create 20MP rasters.

So, I need to find a way to enlarge both the vector and the artboard to a larger size before exporting for jpeg. I have no idea how to do this.

Any help is much appreciated.

Thanks