LEt's just be clear here. There are not NICE guidelines for the Libre, only for CGM.
Likewise, there is not countrywide guidance for adoption of Libre.
At the moment it's dependent on whether your local CCG or group of CCGs has decided whether it will supply Libre, and what criteria it will use to do so. For example, London CCGs are not yet providing it as they are collectively deciding what approach they will take. Meanwhile, a couple in the North East have produced guidance as to who qualifies.
So the first thing you need to do is find out whether it is available in your area.