I'm copying all my stuff from GDrive to an encrypted drive linked to Dropbox. I'm using RCLONE in Windows 10. The thing is that i have a small HDD, i have only 100Gb to cache any content locally. I tried many caching options but the cache continues filing up until runs out of space the computer, no matter which option i use. I tried also disabling the cache but i got many IO Errors and corrupted files in this case.
rclone copy is the way to go, I'm currently doing the same. I'm also doing the copy between the raw remotes, rather than the crypt, I don't know if it makes any difference to throughput but figured that way I wouldn't waste CPU cycles on decrypting/encrypting during the copy process.