Deploying SSRS reports on an "Air Gapped" report server without SSDT?

Whats the simplest way to deploy multiple reports (.rdl) alongwith the respective data sources to a machine which cannot be connected to from Visual Studio?

I can only place files at a given location, connect to the report server via remote desktop and execute them.I am not permitted to open firewall ports, or establish any other sort of connectivity between my machine and the report server

One way is to manually upload the files one at a time, which I wish to avoid.