gggggggg:
Then send VOut to A0, and read the value, then double it. Sound right?
Yes. You could optionally add some calibration to get a more accurate value.
Do I even need a reference value?
Technically, you always have a reference. In this case you would use the default which is Vcc (regulated 5V).
And my reference voltage is 2% out from 1.1v.
The bandgap / 1.1V reference would no longer be involved. You can forget about it.
The reference you would be working with is Vcc / 5V.