How to deploy to a remote site with multiple PC's

I have a few sites that have a very slow connection back to the main office but I have a standard 1 GB network at those locations. If I deploy the setup.exe file to one of the off site computers how can I use that install file to install SEP to all the computers at that locaiton? I don't want to push out the install from the main office.

I have seeen where it can deploy using a URL but if I go through the steps and pick the setup.exe I've copied to that location will it run from that offsite locaiton or weill SEPM copy the setup.exe from the offsite computer to the AVS server at the main office then try to upload it to those offsite computers.

Thank you for any help/clues/insite.