iCloud Drive has all the same functionality as the local storage. The only difference is that you might see the file status under the drawing thumbnail:

• Not downloaded. You can download a drawing by tapping on it to open it or by tap+holding and selecting “download”. 

• Downloading/uploading

If the drawing is loaded on the device, it has no status icon. You can remove the download by tap+holding on the drawing and selecting remove download. This leaves the drawing in the gallery, but the next time you open it, the file needs to be downloaded from iCloud.