Vmc also changes depending on altitude, gear and flaps down, C of G etc.
Funnily enough, Vmc goes down with gears out (as they act as rudders and help stabilize). Vmc also goes down at higher altitude as the engine will lose power.
Vmc is determined during the certification process and is done at sea level, gear and flaps up, fully loaded, aft CG - those are the worst conditions. Anything deviating from this will reduce Vmc and therefore increase your control.
Now, would you want to be close to anywhere Vmc in a real engine out situation? Probably not. I can tell you it's pretty sobering experience seeing how little control one has close to those numbers.