The size of a
EPS file does not depend on the DPI settings. DPI only apply for raster graphics such as
The problem you are facing is that the vector image depends on the amount and details of object it is required to contain. So it is highly dependant on the layers you want to display and the amount of objects on these layers. The amount of information that need to be stored in the image also depend on the amount of details on every single object.
EPS stores every path node of every object you want to export. Also it may store any text labels and it will contain the embedded fonts required to display the labels. All that will increase the size of the file.
So it reduce the file you should try to reduce the area you want to export, reduce the amount of labels, reduce the amount of objects by hiding layers and so on.
If all that fails you should think about switching formats. For very wide views on a area, it may be better to use a raster image, such as
JPG. You will not be able to zoom into those images lossless as you are able with the
EPS files and it may a quality drop with very small objects, but the size is not as much dependant on the area you are showing as