All of this is already possible today, even before storj and cunoFS.
- You boot your system via tftp from a nearby (or even remote) server,
- ,the os mounts cloud storage with rclone with local vfs cache, and you have your bottomless disk.
You were so preoccupied with what you could do that you did not stop and think on whether you should 
For this to be effective you need some local caching and/or plenty of ram. 128GB SSD is vastly cheaper than even 8GB of ram, and can fit multiple OS installs. So what would be the point in keeping OS in the cloud, only to download and cache most of it locally anyway?
Local OS is disposable, and best kept local. Data can totally live over cunoFS and Storj. In fact, I’ve been using similar setup of ages – it works very well.
I expect cunoFS to work much better/provide more seamless and compatible FS virtualization, and STORJ to provide excellent connectivity – so this is great news overall of course.