Swift Backup portable data shuttle functionality

Dear community,

I'm working on an Enterprise-Backup Solution with a provider-sided Swift Storage Infrastructure and a client-sided Cloud-Gateway-Appliance with encryption and deduplication functionalities. The initial full backup can easily be several TB of size. Depending on the internet connection, this can result in an initial upload or full download duration of several days, which is not acceptable.
A way round the problem would be an portable physical data shuttle, which collects the encrypted and deduplicated initial backup data from the customers cloud gateway over the customers high-speed network, transfers it by car to the cloud infrastructure, and saves all the data in the customers cloud account over the high-speed network of the cloud infrastructure. The very smaller incremental backups can than be performed on the handed transferred backup data.
Thereby the problem is the gateway-specific data structure (encrypted, deduped).

Is there any experience with such an implementation, maybe some successful solution, or any kind of ideas or doubts whether such a scenario is even possible.

Thanks for any kind of answers.

With regards,
Patrick