For CF11, each Standard license is limited to a single VM with a maximum of 2 cores (section 22.214.171.124.c) or maximum of 5GHz of processing power (126.96.36.199.b) - so you would need a total of four (4) Standard licenses per your specs (the combined processing power of your virtualized hardware might give you some leeway). Enterprise licensing for CF11 can be calculated a variety of ways - by physical CPU of all host servers (it's unclear how many CPUs are covered by a single Enterprise license), by individual VM (each Enterprise license can cover a single VM with up to eight cores, so you would need two (2) Enterprise licenses in this scenario), or by processing power (up to 16GHz per VM).
For CF2016 simplified (but maybe not to your advantage) physical/virtual server licensing by making it strictly based on cores. CF2016 Standard covers a single physical/virtual server with up to two cores - so again, based on your specs, you would need a total of four Standard licenses. CF2016 Enterprise covers a single physical/virtual server with up to eight cores - so you would need two Enterprise licenses (one for each VM).
Keep in mind that Enterprise also allows you to install multiple instances of ColdFusion on the same server. If your requirements permit, you could deploy a single 8-core VM and run two or more instances of ColdFusion on it, with only a single Enterprise license.
Thank you for your helpful answer. I need further clarification on "installing multiple instances of coldFusion":
So if I'm running multiple ColdFusion websites hosted by IIS on one VM, is that the same as creating multiple instances of ColdFusion?
When you said this:
"Standard licenses per your specs (the combined processing power of your virtualized hardware might give you some leeway)."
What does that mean? Does lowering the limits of the virtual hardware decrease the number of licenses you need?