Try downloading a copy of your workflow from usegalaxy.org. It will be in a file that ends with the extension
.ga. That can then be uploaded to the cloud server into your new account.
The first time you open the workflow in the editor, warnings will come up if any tools/tool version are a mismatch for what is already installed on the default server. You can update tools in the workflow, install new tools on the server, etc until things match up. Installing new tool indexes is also possible.
Once you have customized your cloud server (if you need to), you can save an AMI image for reuse. This will cost money to maintain, so if you decide to do this, keeping the image as small as possible would be a good idea (save a copy that does not include full analysis, just what you need to start up a new analysis – permanently delete non-reusable account data, etc).
Workflow objects themselves use up very little space, so you could keep yours in the AMI. Or, download a copy of the workflow configured to work with the GVL default install or your custom AMI. Saving a backup copy is good idea anyway.