Hi gugrim, welcome to the forum.
I think I am understanding you correctly here. I think this has been answered in the past on a different forum: http://stackoverflow.com/questions/11766552/need-to-upgrade-and-relocate-subversion-repo-catch-22
If you can open your working copy in SmartSVN you might use the Modify¦Relocate... option to relocate to the new repository URL. This should then mean that the issue with SmartSVN being unable to access the server is no longer an issue. But I assume that you cannot do this in this case - hence it being a catch 22 situation.
So one option would be to temporarily downgrade your client to a previous version that supports that working copy - you should then be able to relocate. Once you have you should be able to check out from the new repository and upgrade to latest working copy provided you are now using again a later client version.
Another option in this case may be to do a check out from the new repository since it moved and then to add the files and directories from your old working copy to the new working copy manually - you should then be able to add the files to version control by committing to the new repository from the new working copy.
I hope this helps!