I did install a YARP based environment on my droplet along with graphics and it works great. I use it for testing purpose.
The installation in my case was very standard and when it came to graphics I simply searched for online guidance, which is usually super useful on Digital Ocean (DO). This is why I tend to prefer DO over other online premises: it's easy and highly configurable.
An example of how to deal with graphics installation can be found here.
Compared with ROS, YARP is a gentler beast, but I can imagine the installation is still doable, even though you would require definitely a droplet with more resources.