Move Images from wp folder to another location due to server overload

I,m using a reseller account,long term purpose to allow for images folders to spread the server load. I,m just set up a site and already find the 200 images are making the site sluggish.

Using wp how do i link the main site images to any newly created site's in the re seller account.

I have numerous domain names,rather than park i thought i,d use them here.

is this a long winded route,to what i,m trying to archive,which is large folders of images in separate locations to reduce the server load on main.

I have 2 vps,however both are based in the usa,whereas the re seller account is based in Ireland.

Here's hoping i,m making sense