Screen resolution on hyper-v. Please tell me yours

We have about 12 virtual RHEL6.4 machine on MS hyper-v 2012 that have been installed over the last 12 month.

There has always been a issue with the display, it's stuck on a large single resolution with no mechanism to change it. As we do everything via SSH terminal it's never been much of a problem. Now we need to connect via "remote desktop" (either VNC or nomachine nx), and the fixed resolution is causing issues. The usr wants it to occupy their whole screen but the same single resolution is available, which is too small for thier screen (large black boarders)

My question.
When people install RH on hyper-v and connect to it (using hyper-v "connect" feature), do they get a range of resolutions?

Can I manuall hack a X config to create a list of avaialble resolutions?

If there is anything I have about linux it's "X problems". Fortunetly never had then with RH, but plenty with other distros.