Some MC features such as Cover Art management, and particlularly Audio Analysis, would be a nightmare if the music was solely stored on a Cloud service. Audio Analysis needs to read the whole file to work out volume levels and so on. That means downloading every file added to the MC library to analsye it, after you have just uploaded it to the Cloud, and then when you play it, download it again.
I think the simpler solution is to store music locally. Disk space is cheap, and much more cost effective than Cloud storage space. We are talking Terabytes of local storage, but only Gigabytes of Cloud storage. Do all maintenance on MC locally, and then make MC available via the web, for listening on the go. It only requires opening a port in your router, then port forwarding to the appropriate MC Server PC to work, and then a Client that understands MC, or DLNA, to play the tunes. Anybody you give access to can play your music.
Much more sensible for a large collection. The only caveat is that you need a reliable internet connection at home, with a decent upload speed. But if you can't meet that requirement MC gives you the option to synchronise a subset of your collection to a portable device, for music on the go. You could even synchronise a subset of your library to a Cloud service, after analysis and with its Cover Art, plus any DSP if required, if you wanted some music in the Cloud to play elsewhere.