What's the quickest, most efficient way of sending files/proxies to a remote editor (using Premiere) over a moderately slow internet connection? Say that I have many gigabytes of files (4GB) and I want to send them to an editor who lives many miles away. The editor will create a new Premiere project file, edit a couple of sequences and send the project file back to me. This all has to be done within 24 hours.

However, my internet connection is slow and it would take 24 hours for me to upload the files.

Does Adobe CC implement a system that would make this process quicker? Is there a standard workflow that solves this problem?

The solution I have in mind is to send all the files to Encoder and save the output to the cloud. The editor would work with these proxy files. Then once they have sent me the project file, I can link the project to the original clips (I am not exactly sure how I would do this). Is there a better solution?
Sending proxies is also a well established workflow if you choose to go that route. “Offline” and then “Online” editing. 

See the following link for explanation on how to correctly create the proxy files with Premiere Pro

https://helpx.adobe.com/premiere-pro/kb/ingest-proxy-workflow-premiere-pro-cc-2015.html#CreateProxies

Send your Premiere Project and proxy files to your remote editor and receive back the completed project. Import their sequence into your original project and as long as they did not alter the proxies in any way before editing you should be able to reconnect the original media easily.