First of all the sad news. Didn't got the D850 (my Nikon dealer probably wouldn't get it in time for my flight), went with the D810 instead. Already love it.
Now to the Topic - I went with a cloud solution. Or to be more specific, my dad got me a few terabyte on their office server (Which is connected to the german university internet network, which means gigabite connection *Yeah, I guess?*). So yeah, thanks for all your help!