Migrate with access only to source or target

[wouterjanssens]

A customer of me is asking me to migrate from an on prem DevOps Server to Azure DevOps but the security team will not allow a computer in the local network to access both environments at the same time :-(

Is there any way to migrate with these steps:
1: export everything from the source to disk on a client with access to the source
2: move files on disk to another client with access to the target
3: import everything from disk to the target

Thanks in advance for all thoughts on this.

P.S.: Yes I tried several times to provide us an exception to access source and target from a computer (only temporary) but I get a hard NO. It is a government so they are not very flexible in applying security exceptions