My two CWP VMs have more resources than that: 2 CPUs, 6GB of memory on one that runs ~30 accounts, 3CPUs and 10GB of memory on the other "heavy" VM that runs a dedicated Drupal site. That's about the resources I had dedicated to a dedicated e-commerce server running a Magento site.
I've heard of people running servers under 1-2 CPUs and 4GB of memory and I have done that as a temporary measure on my servers, but never long-term.