I was wondering exactly the same - just had my car in the garage as touch screen kept freezing (2012 1.6 Allure). The garage have replaced the touch screen & "updated" all the relevant software apparently.
I asked if it was possible & how much it would be to get sat nav capability on the car - they suggested getting Peugeot Connect Apps as this was cheaper/easier than replacing the unit, but I am not sure if this is true or not?? They also told me that I could link my phone to the HU & be able to use Google Maps via the USB so that this could be used as a sat nav.
Any advice would be greatly appreciated?