The Color Ramp node can output values outside the [0...1] range, but you have to manually input the values inside the field though. The limit of 1 is a soft limit and you can't go below 0.
I just noticed I plugged the color ramp into the Color input of the Emission node, but it works the same way if you plug it into the Strength input, because the color is automatically converted to a float value.
For better usability you can plug a Math node set to Multiply between the color ramp and the emission node.
If you're only going to use 2 grayscale stops on your color ramp, you'll have a better time using a Map Range node.
The From Min and From Max inputs are like the two stop positions on the color ramp axis. The To Min and To Max are equivalent to the stop color values.
Another solution that's more relevant to your problem :
You can set the color ramp stop's color to the emission color and plug the output into the color input of the emission. You can then tweak the emission strength directly.