If you are finding it unrealistic to handle multiple cloud accounts and are looking for a solution to move all your data to a single account, you can make use of Mover. Using this service you do not need to download and re-upload any data. You can transfer data from one service to another just like copying files from one directory to another. Mover has merged with Backup Box which was the previous service. The main features are:
- Supports all major cloud service providers
- Free users get to copy 10GB data
- Users can schedule multiple transfers
- Sign-up is hassle-free and the website is user friendly
- You can see the details of each transfer
- The transfers are automatic, no need to stay online or logged-in
For security, I would recommend changing the passwords of the services and remove Mover app authentication to after your transfer is over.