Store the file to a shared disk, e.g. mount the remote disk locally. Then the usual file access works fine - but slowly. If the file is really huge, e.g. some GB, accessing it through the network will consume much more time than accessing a local copy. The speed difference depends on the reading function and the network speed, but even a factor of 100 is possible.
I'd create a file copy in the local TEMP folder, which is hopefully not duplicated in the cloud-based backup.
