When trying to restore a snapshot I get a the resource you were accessing could not be found error

The Restore Droplet option for Snapshots overwrite’s Droplet’s data with the snapshot’s image. This error occurs when that Droplet your are attempting to restore no longer exists on your account, most likely after deletion.

To work around this error, you can create a new Droplet from your snapshot image. For detailed steps, see our Create New Droplets from a Snapshot guide.

Take a snapshot of your Droplet and then create new Droplet from the snapsnot in the new datacenter.
You cannot create Droplets in certain datacenters due to limited capacity. If you have snapshots in a limited capacity datacenter, transfer them to another datacenter to create Droplets from them.
No, you cannot downsize a Droplet using a snapshot.