Using a Jump Box
A simple but effective way to access your EPN virtual machines is to set up one VM with access using port forwarding. Access to all of the other systems could then be possible from that machine.
This "jump box" could be a specially configured virtual machine or it could be any virtual machine in the deployment you wish to use.
Considerable thought and effort should go into setting up such a machine. Use combinations of EPN port forwarding ingress and egress firewall rules along with whatever internal security on the servers you feel necessary to restrict access to only those systems and people you wish to have access..