So the problem is that the 1DX isn't able to contact the FTP server on the laptop? Can the laptop see the 1DX at all? Does the 1DX have FTP protocols built in, as opposed to LAN protocols? Can they see each other over LAN? I'm not familiar with the 1DX spec, as you can probably tell.
A friend of mine may be open to a challenge at the moment. He's a programmer with some rather special network skills. I described a slightly different scenario to him - file detection and automatic upload to the news editor, which appealed to him - but this sounds more like a connectivity issue.
[edit] Just done some reading up. Assuming you've gone for the FTP mode, rather than WFT, you should be able to connect. I don't think it's one for my mate, tbh.